ObscureCursor
This function temporarily hides the mouse cursor. It reappears when the
mouse moves or upon a subsequent call to ShowCursor.
Notes: This is useful for text editors - when you want to hide the I Beam cursor
while the user is typing.
The cursor is revealed automatically when the mouse moves. This does not
affect the "cursor level" and there is no requirement to match it with a
subsequent call to ShowCursor. However, you may force the cursor to