A few updates to Lumina-desktop
1) Disable the "taskmanager" and "systemtray" panel plugins for now - they are not stable enough for regular use
2) Make sure that panels are actively detroyed as well as created when the settings file changes (depending on what the user settings are)
3) Add a system window for allowing the user to select system shutdown/restart as well as just logout.
Merge branch 'master' of github.com:pcbsd/pcbsd