修改组件数据结构
Merge branch 'dev' of https://github.com/avocadocn/mean into dev

Conflicts:
	app/controllers/group.js
	app/controllers/users.js
	app/views/group/home.jade
	app/views/partials/group_list.jade
	app/views/partials/group_thumbnail.jade
	app/views/users/home.jade