Add registration support (WIP)
Some code cleanup
Merge remote-tracking branch 'origin/Register-branch' into Johan

Conflicts:
	client/src/com/b2/app/ActivityLogin.java
Add login persistence (WIP)
Fix NetworkOnMainThreadException

Not sure if it works, can't test it because IDE broke (again)
Logging in works as intended now

Fix faulty encoding of login data
Add app-token saving
Fix login activity not shutting down when back is pressed