Misc fixes and cleanups
- Improve how the 'active' desktop is tracked (mostly useful for Wayland).
- Make it so
xfdesktop --arrange
sorts all desktops, but the context menu item only sorts the current desktop. - Decouple the user action to manually cycle the backdrop from refreshing/reloading the whole desktop.
- Redesign the 'Desktop Icons' tab in the settings dialog at @lastonestanding's recommendation.
- Fix memory corruption due to a missing signal disconnect when destroying the icon view.
Edited by Brian Tarricone