user32/tests: Skip some tests when DdeClientTransaction() returns NULL. This avoids some crashes on Win9x.

This fixes a render target recreation problem in Age of Empires II.

wined3d: Make sure SFLAG_LOCKED is set at the start of LockRect as various functions called from LockRect depend on it (e.g. LoadTexture if called from LoadLocation).

Instead requeue them into the proper destination queue. Reported by
Ulrich Czekalla.