Added mipmaps to CreateTextureResourceFromFile() for ResourceManager.
All objects except for images and text should now be using mipmaps.
All scenarios where both vertex and index buffers are NULL should now be handled.

Signed-off-by: Markus Tillman <reetopps6@hotmail.com>
Merge branch 'master' of https://github.com/Malow/NDYGFX