dbstructure now switches in the maintenance mode when updating

The account type is now read and displayed

Little fix to the utf8mb4-fix: Now here's the changed database.sql

fix @brief in doxygen for function oembed_iframe()

Fix Issue #2800 - Prevent internal link from switching to Safari in standalone mode

Fix Issue #2813 - Double notification + wrong message for requested registrations

- Add link switch prevention to frio theme
- Add reference to the script page

Add a event delegation to keep internal links inside the standalone
window.

Fixes 1. of #2800

frio: improve readabillity for code blocks

with translations now in /view/lang/lng shift the array index along

Fix #2817 - Move translation language folder in a subfolder of view

Support of utf8mb4

Fix Issue #2823 - Ugly scrollbars in oembed iframes and broken resizing

[Hotfix] Fix #2816 - [Admin] Unable to save config items present in .htconfig.php but not in DB

- Fix _resizeIframe function, shorten the timeout between calls
- Simplify the oembed iframe generation code and reduce the minimum
iframe height to 200px
- Add smooth CSS transition for iframe resizing

Fix #2814

- Change all references to language folders

- Move translation folders under `view/lang`

- Fix wrong variable name in Config and PConfig

- If needed, the version control system can be used to restore this code

- Reverted changes to mod/register.php
- Added "show_in_notification_page" flag to prevent `notify` DB
insertion

- [frio] Add a wrapping `a` tag around the notification text
- Add an event listener preventing popup menus to close when they are
themselves clicked

- Remove adding a notification for each admin on register approval
request
- Fix wrong display of the above notification that is removed anyway
- Fix comments

regenerated messages.po

[frio] Fix terms capitalization

We should only use utf8mb4 for dumpsql and new installations

Add HTML entity decoding to browser notifications

- Revert translation term change for "permissions"

- Changed the translation term "permissions" because only frio is using
it
- Changed the vote links style because it is shared with other themes

[frio] Changes to shared post display (width, base font size)

- Use normal font size for shared content

- Added a bottom margin to the shared header
- Removed padding and horizontal margins for the shared content

This reverts commit 0c383ad9ff.