* Rather than duplicating the decision taking logic involving wheter or not to draw
the outline or glow in every replicant, update be_control_look to make it more
generic.
* The Monitoring of the background preferences is now only done in Tracker (where it
was already being done).
* Add a BControlLook::B_IGNORE_OUTLINE flag to avoid this new behaviour.
* Remove that said logic from ActivityMonitor and use be_control_look.
* Use the ignore flag in DeskCalc to avoid the outline in its case.
Should fix #7716, #7291.