Reframe swallowed windows if depth doesn't match

Reframe swallowed windows if depth doesn't match

X will not allow a window with ParentRelative background to be created
or reparented under a window with mismatching color depth.
Deal with this by destroying the container frame and creating a new one
with the right depth upon swallowing.
Defer destruction of the frame window until after the updated tree has
been rendered to avoid some distracting flickering.

Fixes #3297