* Introduce a configuration to either use the JavaScript compiler or LESS4j

XWIKI-11044: Even you are the creator of an (sub)wiki, the option "Request join" is active on Wiki Index.

* Fix the build.
* Improve a bit the UI code.

XWIKI-11035: Applications Panel's submenu items are misaligned when the Font Awesome Icon Theme is used.

* Applying the CSS codestyle too.

XWIKI-11044: Even you are the creator of an (sub)wiki, the option "Request join" is active on Wiki Index.

XWIKI-11129: Wrong message received if you want to reset your password and the SMTP server isn't configured

* fix test

XWIKI-11154: Impossible to download extension file from REST when the extension file link is a URL that does not provide any content type

XWIKI-11126: Wording issues on Administration -> Presentation

* Display the current language in the top bar if multilingual=1
* Also remove the .hasIcon CSS class which is actually useless in Flamingo

- Properly implemented for all NumberClass types

XWIKI-10296: The default value of a date field should be empty or today, not the date when the class has been created
- Using a magic date to mark inside an application's template that a default value is not actually set and that the emptyIsToday mechanism should still be applied when creating new entries.
- Used a custom displayer for Date fields that displays an empty value in the AWM class editor or the entry's edit/create form when the magic value is set to the template so that the user is never exposed to this technical detail.

XWIKI-11100: The Color Themes picker isn't properly displayed when using the scrollbar.

This reverts commit 8be389b7.

- Fixing selector

Fixed.

XWIKI-11110: Document translations are not marked correctly with translation=1 in the database of a newly created wiki
* fix mistakes

XWIKI-11110: Document translations are not marked correctly with translation=1 in the database of a newly created wiki
* make sure it cannot really happen anymore