Add TextButton
Add Direction Enumeration

This will be useful later. I'm surprised HaxeFlixel doesn't have one of
these already.
Add shorthand Property to Direction
Add Global Constant List
Add CableSegment

A cable segment is one tile's worth of cable. It changes its appearance
based on its neighbors in the cable.
Fix Animation Bug in Cable Segment

Fixes a problem where the animation names were not always generated with
the exits in the right order.
Organize Animations in Priority Order
Add Outlet Class