A3DGE Code

* Fixed default camera light location.
* Fixed name of unit a3dge.Heightmap.
* Improved the heightmap system. It also uses a bitmap instead of a propietary
file format.
* Fixed application Run by ensuring the gamestate is initialized.
* Fixed PLG colours. Still not perfect though.
* Fixed Wavefront .obj file loader issue when file doesn't define face normals.
* Fixed skybox texture loading that generated rendering glitches due to the use
of rendering filters and mip-maps.
+ ex_world loads and renders a heightmap now. Also added mouse speed, fog,
light and some movement.
+ Added light to objview.