fixed collisions for Circle and Polygon with other masks,
fixed Projection.overlaps() which really means !overlaps,
added pivot point to Polygon.debugDraw(),
still missing support for collisions against SlopedGrid and PixelMask
Streamlined HP.indexOf (optimized for dynamic platforms)
Merge branch 'fix/collisions' of git://github.com/azrafe7/HaxePunk into azrafe7-fix/collisions

Conflicts:
	com/haxepunk/HXP.hx
	com/haxepunk/masks/Polygon.hx