Bug 924: Fix X11 Fullscreen ALT-TAB Regression ; Make ALWAYS_ON_TOP Persistent when Reparenting (child -> top)
- X11 Fullscreen ALT-TAB regression (no task-switcher visible) We still need the fast reconfigure path for ALWAYSONTOP only toggle. It was removed w/ commit c9fcc8cd510abc0cbebb872dc3e457327655e778, which disabled toggling FULLSCREEN and ALWAYSONTOP.
Note: Another bug in Unity WM's Compiz: 'Unredirect Fullscreen Windows := True' disables the ALT-TAB taskbar/launcher HUD rendering and subsequent task-switch. Hence it shall be disabled .. nothing we can do here.
- ALWAYS_ON_TOP not persistent when child -> top WM removes ALWAYS_ON_TOP state when reparenting, hence reinforce it when Child -> Top.