Basic battle state. Cleanups.

Added basic battle logic - drawing and toggling of combatants.

Re-factored and cleaned up code. to fix jsHint warnings.
Scaling based on keyboard input.

Added simple scaling based on keyboard input. Currently, scaling is
implemented in two places - for the level and for the battle screen.
Ideally, a global scaling system for everything except UI should be
implemented.
Merge remote-tracking branch 'origin/master' into gh-pages