Fix masklist drawing collision

- Added project() to Hitbox (now handling offsets)
- Added min/max coords to Polygon
- Masklist updated to differentiate between Hitbox and Polygon (to handle bounds correctly)

This builds on top of #252, addressing #241 and #256.

Minitest: https://github.com/azrafe7/HaxePunk-minitests/tree/master/SimpleTestHitboxMasklist

![](https://dl.dropboxusercontent.com/u/32864004/dev/FPDemo/fixed-masklist.png)