[Zhenghan] Sort by time & by likes. Small improvements.
Merge remote-tracking branch 'origin/master'

Conflicts:
	app/js/controllers.js
	app/partials/around.html
	app/partials/idea.html
[Zhenghan] Split register/login module. Marquee page added. Bug fixed
[Zhenghan] Tag system built. Bug fixed
[Zhenghan] Tag lib added
[Zhenghan] MVP application & comment categories