3D tile wireframe display is tangled

[chris-cooper]

There's some assumptions in the code that triangle winding will support display as a LINES primitive which seem unlikely with real world data. e.g. in the sandcastle

[OmarShehata]

I'm marking this as an enhancement because I think the current debugWireframe mode is intended for debug purposes, and a nicer looking wireframe for presentation would need a different technique.

[3DGISKing]

Maybe we need the additional renderer resource(index buffer) in Model for correct rendering wireframe.