Reuse image and mask DCs.

- Add Mac OS X signal support.

introduced through Win98 are included.

- Partially implement PropVariantCopy.
- Implement FreePropVariantArray.

Fix a few signed/unsigned warnings.

forwarded export.

use 'ptr'.

not multiple sets of polygons.

piping the PostScript through something before it gets sent to the
printer (like we can already do for non-cups systems).

Fixed a memory leak.

- minor indentation and traces fixes
- fix locking/unlocking/dirty behavior (dirtify on lock) +
  optimisations (only copy when dirty)
- fix IDirect3DDevice8::Clear behavior (problem seen after a
  locking/unlocking code error)
- begin to fix volume and cube textures management

- added handling for some new texturing ops
- prepare for addition of multi-texturing
- another way to fix the device enumeration for the reference device
- fix compilation with some glext.h files
- fix a bug in one texture conversion function
- added new texture format (but still texturing problems in 3DMark2000)

- added locking for concurrent access to the D3D device
- improved tracing
- added support for most texture combine stages (inspired by the D3D8
  code)
- disable current lock / unlock code pending proper solution