Added case details activity.
* Added gallery using recyclerView
added difficulty rating bar
Finished first details activity layout design.
Minor color refactorings throughout the app.
Added logic for getting case details from server
Bug fixes. getting details from server works now
Image retrieval separated from case retrieval.
Refactoring to remove processing on the main thread.
Moved processing from main thread to background in cases activity.
Networking moved to a different thread. Added loading bar.
Added on click listener in gallery.
Fixed button bug in login screen.
Added on click handling for case images
* Added PhotoView library for image control.
* Added the use of a singelton to pass case files between activities.
Added discussions activity
Minor refactoring before merging
Merge branch '7_add_details_activity'