rpcrt4: Use pseudo-random numbers to generate UUIDs rather than using the (old, deprecated) MAC-address-and-time generation algorithm.

quartz: Only test for the presence or absence of a single filter in a loop. Testing for more than one depends on the order of enumeration, which isn't guaranteed.

dinput: Add test to show that effects are stopped after Unacquire + Acquire and preserved in dinput.

The ME_InvalidateFromOfs and ME_QueueInvalidateFromCursor functions are
never called, and the nInvalidOfs variable had its value set but never
used.

I noticed a while ago that on Windows XP richedit controls ignored
characters typed while the mouse is captured (e.g. from holding the left
or middle button down).  Arrow keys, delete, and backspace, copying,
cutting, pasting, and everything else handled on WM_CHAR and WM_KEYDOWN
messages are also ignored.

Ignore some more registered messages.
Fix some other failures on Win2k.

user32/tests: Ignore WM_IME_SELECT message. Skip mouse hovering test if the mouse isn't where we want.