Make "like" links one way

- Updated dolike() function to accept a "un-" switch
- [frio] Updated doLikeAction() function to call dolike() instead of having duplicated code
- Added boolean logic (with explanatory truth table) to smartly delete existing activities in Model\Item::performActivity
- Moved verb/activity parameter handling closer to their use in Model\Item::performActivity
- Updated all references to dolike() and doLikeAction() to include the "un-" switch

view/theme/frio/js/theme.js

@@ -721,22 +721,17 @@ function htmlToText(htmlString) {
  * Sends a /like API call and updates the display of the relevant action button
  * before the update reloads the item.
  *
- * @param {string} ident The id of the relevant item
- * @param {string} verb The verb of the action
- * @returns {undefined}
+ * @param {int}     ident The id of the relevant item
+ * @param {string}  verb  The verb of the action
+ * @param {boolean} un    Whether to perform an activity removal instead of creation
  */
-function doLikeAction(ident, verb) {
-	unpause();
-
+function doLikeAction(ident, verb, un) {
 	if (verb.indexOf('attend') === 0) {
 		$('.item-' + ident + ' .button-event:not(#' + verb + '-' + ident + ')').removeClass('active');
 	}
 	$('#' + verb + '-' + ident).toggleClass('active');
-	$('#like-rotator-' + ident.toString()).show();
-	$.get('like/' + ident.toString() + '?verb=' + verb, NavUpdate );
-	liking = 1;
-	force_update = true;
-	update_item = ident.toString();
+
+	dolike(ident, verb, un);
 }
 
 // Decodes a hexadecimally encoded binary string