Workaround dumb custom texture loading logic.

Basically, most (all?) non-RGBA32 textures failed to load on D3D (and other platforms which require all textures to be loaded as RGBA32) before. I have had this workaround lie around on my disk for ages now and I just can't get myself motivated to work on a proper fix.

Take this workaround or wait for someone to do a proper fix, but I'm done with the issue for now :p