Implemented material which renders a silhouette over obstructing objects.
- added SilhouetteMaterial.as. SilhouetteMaterial uses SilhouetteMaterialPass.as to first render the silhouette over obstructing objects, then the actual object. SilhouetteMaterial.as currently extends ColorMaterial.
- added SilhouetteMaterialPass.as. SilhouetteMaterialPass sets the compare mode to GREATER in the activate function and prevents the pass to write into the depth buffer.