user32: Make WINPROC_AllocProc take a unicode flag for consistency with the other winproc functions.

Found by Valgrind.

Fixes a regression introduced by ef522c5e.

The sort function used by native is not entirely consistent with lstrcmpiW,
even on Windows.

Found by Valgrind.

The next patch uses this.

I originally kept these when adding surface_init() in
5f581975 because the original code had them on
most error paths. However, this actually broke ddraw because it assumed we
don't touch "ppSurface" on errors. Just remove these since they're useless
anyway.

ddraw: Don't depend on IWineD3DDevice_CreateSurface() not touching the surface parameter on failure.

The reason it actually fails is because of ddraw trying to create surface of
type "SURFACE_UNKNOWN". Stefan should have a patch for that.