Implement signed d3d formats for D3DFMT_V8U8 and D3DFMT_Q8W8V8U8 if no
suitable opengl signed format is supported.

riched20: Add a test that shows that under Win9x RichEdit20W windows are not unicode, but always expect to see unicode input.

ole32: The 16-bit version of CoDisconnectObject is not compatible with the 32-bit version, so create a separate stub for the former.

winedump: Fix the output for Makefile.in with respect to the dependencies line to match that required by the build system.

Move the checks for float texture formats into the correct location.
This allows some Direct3D sample applications which check for any of
the float formats together with D3DUSAGE_RENDERTARGET to start.

wined3d: Ensure all states affected by a change in render_offscreen are marked dirty in ActivateContext.