Add action type to screen edge show to allow raise/lower as well as
autohide
Add an action type to screen edge show to allow raise/lower as well as
autohide. This uses the same atom, using a mask to separate type and
location.
The logic for handling geometry changes is moved from the screenedge to
the client so that we can handle both types without screenedge needing
to know what the raise is for.
REVIEW: 124272
