Based on a patch sent by Matthew Kehrer a while ago.

Map:
D3DFMT_L16 -> GL_LUMINANCE16_EXT
D3DFMT_A16B16G16R16 -> GL_RGBA16_EXT
as Raphael suggested.

Also increase the returned Bpp for unknown and unhandled formats from
4 to 8 bytes - this part fixes segfault in the F.E.A.R demo. It now
shows some flashy graphics before it dies again :)

Fix 2 bugs in the error paths of the ds3d.c test (coverity).

- Fix ref counting.
- Use This->window instead of QI in NSContainer_Release.