Use Less CSS pre-processor

The goal of this change is to improve the maintainability of the CSS and
decrease code duplication.
Improve UI

Improve script loading
Update AngularCache
Small UI fix
[fix #113] Remove editor settings from the menu

Remove editor settings from the menu
[add #114] Add the possibility to delete account

Users can remove his own profile directly in the profile page.
[fix #109] Fix reset password in profile page

The rest function was never call and fix the request.
[add #111] Add tooltip on buttons

Add a tooltip on each button to explain the functionality of it.
[fix #108] Protect paper data when leaving
Don't display two identical messages
Fix TOC display

Improve diplay of ignored section
Add a compilation indicator

Display a spin when a compilation launched by a user is active (at the
right of "compile" in the top of the paper page).
Add a progress bar for the PDF rendering

Display a progress bar which indicates the progression of the PDF parse.
Improve SyncTeX support

Improve PDF -> code source, now the correct file associate to the PDF
zone is found.
Udapte AngularJS to v1.2.22
Update ACE Editor to v1.1.6
Improve LaTeX autocompletion

Improve autocompletion list.
Search label created by the user and add them into the auto completion list