maddog: More work on Mad Dog McCree.

Implmented the town crossroads level chooser and the Saloon level.

Hitboxes are now colorized to what type of thing you're shooting at.

Added input tolerances, so we'll accept actions that should have passed if they
passed between the current tick and last one, which helps smooth over maddog's
small hitbox windows but also might save you if your computer is lagging.

Lots of other little fixes.

Author: icculus