Group H Class Materials & Assignments

DRAFT PR DON'T MERGE YET

Reviewers: @haxcb 

Class materials and assignments front-end for both instructors and students, as specified in http://teamtoo.boards.net/thread/24/master-collection-screens 

Highlights
* Added InAppBrowser plugin to open PDFs 
* Embedded YouTube player for video content
* TextAngular WYSIWYG editor https://github.com/fraywing/textAngular/wiki (I have no idea if this works)
* Lots of static data in www/js/services.js 
* No server calls

Possible integration problems
* Lots of static data in www/js/services.js 
* User roles are represented by the userModel factory