Direct3D 9 Bug Fixes *Merge*

Figured out what was causing the texture binding problems with models, I
partly had GetPrimCount on primitives wrong, the function should return
the number of triangles on the primitive for DX. I also was creating an
index buffer on models which did not need them, and was not enabling the
correct blend mode in screen_init, I also had to remove normals from the custom FVF as having normals even when lighting is disabled, makes the model all black. The only problem left is having DX's
sprite batching class running at the same time you draw a model or make a
call to SetFVF, it will make it so there is no backface culling on
objects, will investigate more. Please merge when ready.