[project] enabled strict mode in all files

forgot to add "use strict" to js/data/merger.js and js/data/interpreter.js
Merge branch 'version-0.5' into develop
[project] implemented a stricter content security policy
[project] css -> less
[project] removed /css, added to .gitignore
[project] updated Makefile for less, added bin/watch-src

run bin/watch-src while developping, it wil automatically rebuild
the CSS files in /css on every edit.
[project] js -> coffee

Made the move from javascript to coffeescript
All scripts seem to work, more excessive testing is advised though
[backend] fixed null pointer
[project] updated watch-src and html files for coffee
[project] updated Makefile for coffeescript
[project] updated content security policy

allow "unsafe-inline" for style, this fixes issue with cursor
when dragging a panel on the options page
[project] use glob in web accessible resources
Merge branch 'dev-less' into develop

Conflicts:
	manifest.json
[project] coffee --join is deprecated
see jashkenas/coffeescript@1cd48a9f5d38e823434c6c00ba41846270535a47
[project] split content.js in parts
[project] small tweak
[project] removed old JS map files from WAR
[content] small tweak
[content] removed console.log
I/O is slow :)
[content] fix for +mentions