Add ng-file-upload
Add global clicakable global css class
Implement Assetmanagement

Includes:
- Tag creation
- Image Upload
- Assigning of Assets to Canvas
- Removing of Assets from Canvas
Fix "back to project" button in canvasView

Please don't ask me why. But this only works correctly if those dependencies are loaded twice... Once before and once after angular.js.
Improve "go back to project" button in canvasView
Prevent editing Projects that the user may not

edit because he is not enrolled...
Merge remote-tracking branch 'upstream/master'
Fix login management

fixes issue #48
Merge pull request #46 from tobiasmuecksch/master

Implement Assetmanagement