diff --git a/include/plugin.php b/include/plugin.php
deleted file mode 100644
index 0059b7d86..000000000
--- a/include/plugin.php
+++ /dev/null
@@ -1,467 +0,0 @@
-<?php
-/**
- * @file include/plugin.php
- *
- * @brief Some functions to handle addons and themes.
- */
-
-use Friendica\App;
-use Friendica\Core\Config;
-use Friendica\Core\System;
-use Friendica\Database\DBM;
-
-/**
- * @brief uninstalls an addon.
- *
- * @param string $plugin name of the addon
- * @return boolean
- */
-function uninstall_plugin($plugin) {
-	logger("Addons: uninstalling " . $plugin);
-	dba::delete('addon', ['name' => $plugin]);
-
-	@include_once('addon/' . $plugin . '/' . $plugin . '.php');
-	if (function_exists($plugin . '_uninstall')) {
-		$func = $plugin . '_uninstall';
-		$func();
-	}
-}
-
-/**
- * @brief installs an addon.
- *
- * @param string $plugin name of the addon
- * @return bool
- */
-function install_plugin($plugin) {
-	// silently fail if plugin was removed
-
-	if (!file_exists('addon/' . $plugin . '/' . $plugin . '.php')) {
-		return false;
-	}
-	logger("Addons: installing " . $plugin);
-	$t = @filemtime('addon/' . $plugin . '/' . $plugin . '.php');
-	@include_once('addon/' . $plugin . '/' . $plugin . '.php');
-	if (function_exists($plugin . '_install')) {
-		$func = $plugin . '_install';
-		$func();
-
-		$plugin_admin = (function_exists($plugin."_plugin_admin") ? 1 : 0);
-
-		dba::insert('addon', ['name' => $plugin, 'installed' => true,
-					'timestamp' => $t, 'plugin_admin' => $plugin_admin]);
-
-		// we can add the following with the previous SQL
-		// once most site tables have been updated.
-		// This way the system won't fall over dead during the update.
-
-		if (file_exists('addon/' . $plugin . '/.hidden')) {
-			dba::update('addon', ['hidden' => true], ['name' => $plugin]);
-		}
-		return true;
-	} else {
-		logger("Addons: FAILED installing " . $plugin);
-		return false;
-	}
-}
-
-// reload all updated plugins
-
-function reload_plugins() {
-	$plugins = Config::get('system', 'addon');
-	if (strlen($plugins)) {
-
-		$r = q("SELECT * FROM `addon` WHERE `installed` = 1");
-		if (DBM::is_result($r)) {
-			$installed = $r;
-		} else {
-			$installed = [];
-		}
-
-		$parr = explode(',',$plugins);
-
-		if (count($parr)) {
-			foreach ($parr as $pl) {
-
-				$pl = trim($pl);
-
-				$fname = 'addon/' . $pl . '/' . $pl . '.php';
-
-				if (file_exists($fname)) {
-					$t = @filemtime($fname);
-					foreach ($installed as $i) {
-						if (($i['name'] == $pl) && ($i['timestamp'] != $t)) {
-							logger('Reloading plugin: ' . $i['name']);
-							@include_once($fname);
-
-							if (function_exists($pl . '_uninstall')) {
-								$func = $pl . '_uninstall';
-								$func();
-							}
-							if (function_exists($pl . '_install')) {
-								$func = $pl . '_install';
-								$func();
-							}
-							dba::update('addon', ['timestamp' => $t], ['id' => $i['id']]);
-						}
-					}
-				}
-			}
-		}
-	}
-
-}
-
-/**
- * @brief check if addon is enabled
- *
- * @param string $plugin
- * @return boolean
- */
-function plugin_enabled($plugin) {
-	return dba::exists('addon', ['installed' => true, 'name' => $plugin]);
-}
-
-
-/**
- * @brief registers a hook.
- *
- * @param string $hook the name of the hook
- * @param string $file the name of the file that hooks into
- * @param string $function the name of the function that the hook will call
- * @param int $priority A priority (defaults to 0)
- * @return mixed|bool
- */
-function register_hook($hook, $file, $function, $priority=0) {
-	$condition = ['hook' => $hook, 'file' => $file, 'function' => $function];
-	$exists = dba::exists('hook', $condition);
-	if ($exists) {
-		return true;
-	}
-
-	$r = dba::insert('hook', ['hook' => $hook, 'file' => $file, 'function' => $function, 'priority' => $priority]);
-
-	return $r;
-}
-
-/**
- * @brief unregisters a hook.
- *
- * @param string $hook the name of the hook
- * @param string $file the name of the file that hooks into
- * @param string $function the name of the function that the hook called
- * @return array
- */
-function unregister_hook($hook, $file, $function) {
-	$condition = ['hook' => $hook, 'file' => $file, 'function' => $function];
-	$r = dba::delete('hook', $condition);
-	return $r;
-}
-
-
-function load_hooks() {
-	$a = get_app();
-	$a->hooks = [];
-	$r = dba::select('hook', ['hook', 'file', 'function'], [], ['order' => ['priority' => 'desc', 'file']]);
-
-	while ($rr = dba::fetch($r)) {
-		if (! array_key_exists($rr['hook'],$a->hooks)) {
-			$a->hooks[$rr['hook']] = [];
-		}
-		$a->hooks[$rr['hook']][] = [$rr['file'],$rr['function']];
-	}
-	dba::close($r);
-}
-
-/**
- * @brief Calls a hook.
- *
- * Use this function when you want to be able to allow a hook to manipulate
- * the provided data.
- *
- * @param string $name of the hook to call
- * @param string|array &$data to transmit to the callback handler
- */
-function call_hooks($name, &$data = null)
-{
-	$a = get_app();
-
-	if (is_array($a->hooks) && array_key_exists($name, $a->hooks)) {
-		foreach ($a->hooks[$name] as $hook) {
-			call_single_hook($a, $name, $hook, $data);
-		}
-	}
-}
-
-/**
- * @brief Calls a single hook.
- *
- * @param string $name of the hook to call
- * @param array $hook Hook data
- * @param string|array &$data to transmit to the callback handler
- */
-function call_single_hook($a, $name, $hook, &$data = null) {
-	// Don't run a theme's hook if the user isn't using the theme
-	if (strpos($hook[0], 'view/theme/') !== false && strpos($hook[0], 'view/theme/'.current_theme()) === false)
-		return;
-
-	@include_once($hook[0]);
-	if (function_exists($hook[1])) {
-		$func = $hook[1];
-		$func($a, $data);
-	} else {
-		// remove orphan hooks
-		$condition = ['hook' => $name, 'file' => $hook[0], 'function' => $hook[1]];
-		dba::delete('hook', $condition);
-	}
-}
-
-//check if an app_menu hook exist for plugin $name.
-//Return true if the plugin is an app
-function plugin_is_app($name) {
-	$a = get_app();
-
-	if (is_array($a->hooks) && (array_key_exists('app_menu',$a->hooks))) {
-		foreach ($a->hooks['app_menu'] as $hook) {
-			if ($hook[0] == 'addon/'.$name.'/'.$name.'.php')
-				return true;
-		}
-	}
-
-	return false;
-}
-
-/**
- * @brief Parse plugin comment in search of plugin infos.
- *
- * like
- * \code
- *...* Name: Plugin
- *   * Description: A plugin which plugs in
- * . * Version: 1.2.3
- *   * Author: John <profile url>
- *   * Author: Jane <email>
- *   *
- *  *\endcode
- * @param string $plugin the name of the plugin
- * @return array with the plugin information
- */
-
-function get_plugin_info($plugin) {
-
-	$a = get_app();
-
-	$info=[
-		'name' => $plugin,
-		'description' => "",
-		'author' => [],
-		'version' => "",
-		'status' => ""
-	];
-
-	if (!is_file("addon/$plugin/$plugin.php")) return $info;
-
-	$stamp1 = microtime(true);
-	$f = file_get_contents("addon/$plugin/$plugin.php");
-	$a->save_timestamp($stamp1, "file");
-
-	$r = preg_match("|/\*.*\*/|msU", $f, $m);
-
-	if ($r) {
-		$ll = explode("\n", $m[0]);
-		foreach ( $ll as $l ) {
-			$l = trim($l,"\t\n\r */");
-			if ($l != "") {
-				list($k,$v) = array_map("trim", explode(":",$l,2));
-				$k= strtolower($k);
-				if ($k == "author") {
-					$r=preg_match("|([^<]+)<([^>]+)>|", $v, $m);
-					if ($r) {
-						$info['author'][] = ['name'=>$m[1], 'link'=>$m[2]];
-					} else {
-						$info['author'][] = ['name'=>$v];
-					}
-				} else {
-					if (array_key_exists($k,$info)) {
-						$info[$k]=$v;
-					}
-				}
-
-			}
-		}
-
-	}
-	return $info;
-}
-
-
-/**
- * @brief Parse theme comment in search of theme infos.
- *
- * like
- * \code
- * ..* Name: My Theme
- *   * Description: My Cool Theme
- * . * Version: 1.2.3
- *   * Author: John <profile url>
- *   * Maintainer: Jane <profile url>
- *   *
- * \endcode
- * @param string $theme the name of the theme
- * @return array
- */
-
-function get_theme_info($theme) {
-	$info=[
-		'name' => $theme,
-		'description' => "",
-		'author' => [],
-		'maintainer' => [],
-		'version' => "",
-		'credits' => "",
-		'experimental' => false,
-		'unsupported' => false
-	];
-
-	if (file_exists("view/theme/$theme/experimental"))
-		$info['experimental'] = true;
-	if (file_exists("view/theme/$theme/unsupported"))
-		$info['unsupported'] = true;
-
-	if (!is_file("view/theme/$theme/theme.php")) return $info;
-
-	$a = get_app();
-	$stamp1 = microtime(true);
-	$f = file_get_contents("view/theme/$theme/theme.php");
-	$a->save_timestamp($stamp1, "file");
-
-	$r = preg_match("|/\*.*\*/|msU", $f, $m);
-
-	if ($r) {
-		$ll = explode("\n", $m[0]);
-		foreach ( $ll as $l ) {
-			$l = trim($l,"\t\n\r */");
-			if ($l != "") {
-				list($k,$v) = array_map("trim", explode(":",$l,2));
-				$k= strtolower($k);
-				if ($k == "author") {
-
-					$r=preg_match("|([^<]+)<([^>]+)>|", $v, $m);
-					if ($r) {
-						$info['author'][] = ['name'=>$m[1], 'link'=>$m[2]];
-					} else {
-						$info['author'][] = ['name'=>$v];
-					}
-				} elseif ($k == "maintainer") {
-					$r=preg_match("|([^<]+)<([^>]+)>|", $v, $m);
-					if ($r) {
-						$info['maintainer'][] = ['name'=>$m[1], 'link'=>$m[2]];
-					} else {
-						$info['maintainer'][] = ['name'=>$v];
-					}
-				} else {
-					if (array_key_exists($k,$info)) {
-						$info[$k]=$v;
-					}
-				}
-
-			}
-		}
-
-	}
-	return $info;
-}
-
-/**
- * @brief Returns the theme's screenshot.
- *
- * The screenshot is expected as view/theme/$theme/screenshot.[png|jpg].
- *
- * @param sring $theme The name of the theme
- * @return string
- */
-function get_theme_screenshot($theme) {
-	$exts = ['.png','.jpg'];
-	foreach ($exts as $ext) {
-		if (file_exists('view/theme/' . $theme . '/screenshot' . $ext)) {
-			return(System::baseUrl() . '/view/theme/' . $theme . '/screenshot' . $ext);
-		}
-	}
-	return(System::baseUrl() . '/images/blank.png');
-}
-
-// install and uninstall theme
-function uninstall_theme($theme) {
-	logger("Addons: uninstalling theme " . $theme);
-
-	include_once("view/theme/$theme/theme.php");
-	if (function_exists("{$theme}_uninstall")) {
-		$func = "{$theme}_uninstall";
-		$func();
-	}
-}
-
-function install_theme($theme) {
-	// silently fail if theme was removed
-
-	if (! file_exists("view/theme/$theme/theme.php")) {
-		return false;
-	}
-
-	logger("Addons: installing theme $theme");
-
-	include_once("view/theme/$theme/theme.php");
-
-	if (function_exists("{$theme}_install")) {
-		$func = "{$theme}_install";
-		$func();
-		return true;
-	} else {
-		logger("Addons: FAILED installing theme $theme");
-		return false;
-	}
-
-}
-
-/**
- * @brief Get the full path to relevant theme files by filename
- *
- * This function search in the theme directory (and if not present in global theme directory)
- * if there is a directory with the file extension and  for a file with the given
- * filename.
- *
- * @param string $file Filename
- * @param string $root Full root path
- * @return string Path to the file or empty string if the file isn't found
- */
-function theme_include($file, $root = '') {
-	$file = basename($file);
-
-	// Make sure $root ends with a slash / if it's not blank
-	if ($root !== '' && $root[strlen($root)-1] !== '/') {
-		$root = $root . '/';
-	}
-	$theme_info = get_app()->theme_info;
-	if (is_array($theme_info) && array_key_exists('extends',$theme_info)) {
-		$parent = $theme_info['extends'];
-	} else {
-		$parent = 'NOPATH';
-	}
-	$theme = current_theme();
-	$thname = $theme;
-	$ext = substr($file,strrpos($file,'.')+1);
-	$paths = [
-		"{$root}view/theme/$thname/$ext/$file",
-		"{$root}view/theme/$parent/$ext/$file",
-		"{$root}view/$ext/$file",
-	];
-	foreach ($paths as $p) {
-		// strpos() is faster than strstr when checking if one string is in another (http://php.net/manual/en/function.strstr.php)
-		if (strpos($p,'NOPATH') !== false) {
-			continue;
-		} elseif (file_exists($p)) {
-			return $p;
-		}
-	}
-	return '';
-}