App conforms more to mvc with the model notifying all of its views to change when the model changes
More changes to SelectUsernameActivity
xml changes
Image is shown as thumbnail in lists, and displayed fully in topic and comment views

Merge branch 'MvcChanges' of https://github.com/CMPUT301W14T13/Team13GPSCommentLogger into ReplyToComment

Conflicts:
	GPSCommentLogger/src/com/CMPUT301W14T13/gpscommentlogger/view/CreateSubmissionActivity.java