Added Database
Database now working
Calculates the time difference between close open

The database now saves the time and variables when shut down and
calculates the time difference between two sessions.
Added java doc and comments
few changes
Merge branch 'poo_sprint' into Dev
merge Dev into Database
MainActivity after conflict
Merge branch 'Dev' into Database

Conflicts:
	CrayCray/src/se/chalmers/dat255/craycray/MainActivity.java
MainActivity
Merge branch 'Dev' into Database
Merge branch 'Database' into Dev
mergefix
apk and pictures