d3d9/tests: Test that Direct3D9 doesn't modify the pixel format of the window it targets. (try 4, resend).

wined3d: Make context_update_window() just mark the GL context as needing to be set rather than setting it.

The new needs_set flag can be cleared after it's been heeded whereas restore_ctx
must not be cleared until the context has been released back to level 0.

It calls context_set_gl_context() just after and that starts with a call to
context_set_pixel_format().  Also, context_update_window() didn't do the
right thing (fall back to swapchain backup DC) if context_set_pixel_format()
fails.

wined3d: Call context_enter() before context_update_window() so it records the proper restore state.

Spotted by Aric Stewart.