[wysiwyg] Integrated Morrigan

http://morrigan-editor.org/
[morrigan] Internationalised titles
[morrigan] More internationalisation
[morrigan] Default initialisation values
[morrigan] Set size
[chat.js] Fixed current user management
[login] Translate exceptions
[initialisation] Fixed paths
[js] Some missing semicolons
Merge remote branch 'origin/guimier-wysiwyg' into drogue-design

Conflicts:
	default/languages/en.json
	default/languages/fr.json
Documented directories structure

Moved `Post.php` to `/common/channels`.
The `local/data` shown structure is the future one, not the current.
[README] small fix
[language selector] Same appearance on both pages
[css/button] Same appearance for all buttons

We should not style them on a per-case basis.
[css/select] :hover behaviour buttons.

Factorised similar properties between inputs & selects.
[WIP] Morrigan integration in interface
Merge branch 'master' into drogue-design