A few fixes and changes (Sorry this isn't very atomic)

1. Initial refactor: PauseMenu now is a separate menu class. It's kind
of a trivial move, I plan to generalize this soon

2. Cooldown-related warning fixed. Cooldowns are now signed integers.

3. Temporarily kludge: words::draw method just uses the interface's
drawGlyph function
Merge branch 'alpha' of github:Advael/gannicus into alpha