Renamed polygon to PolygonRenderer; Added polygon (as a list of points)
Added collision polygons to scene element
Updated techdemo to use collision polygons in triangle
Added test for collision polygons
Fixing a couple of broken scenes in tech demo
Removed comment; improved collision polygon test
Merge pull request #4 from jtorrente/pr/208

Fixing a couple of broken scenes in tech demo
Merge pull request #208 from anserran/collision-polygons

Added collision polygons to scene elements