Resolved rotation crash in GuessActivity (null reference)
Added primitive scoring system (can be changed if we wanna get cool)
Tweaked layouts a bit (added an indication of who the artist/drawer is

Looks good for checkpoint! GJ guys! Activities are both pretty much
done, we can all chip in on Amin's part (the view) where needed. Once we
get the actual drawing part to work, we're all set!