Added more Parse functionality:
	- Parse login
	- Anonymous user
Automatically moves to semester activity if user is already logged in
Back button functionality kills login activity, moves back to main page instead of back to login
Merge branch 'master' of github.com:rmcmanus/Mobile-Application-3

Conflicts:
	HunterMcManus-App3/res/values/strings.xml
Giving up for the night. Pretty sure I've finished all the login stuff for Parse. Should probably:
	- Add password validation (password -> confirm password)
	- Change username to email

Will work on fragments in the morning, but my brain is a little fragged. Enjoy!