TODOs for Theme manager:
* check R5 build
* style cleanup (-> Haiku style)
* enable theme descriptions again (tooltip on listitem ?).
* make ParseMessage more robust
* forbid quitting while themes are loading!
* implement BackupFiles() methods to add required files to a zip.
* fix TerminalAddon: get theme from haiku
* Save as resource/BMessage ? (for editing)
* broadcast _UIC for Haiku
* ideas for addons:
	- ~/config/settings/Tracker/DefaultFolderTemplate/ (default background ??)
	- Desktop icon size ?
	- Desktop shelf ? (dangerous)
	- Deskbar logo (Be, leaf...)
	- dircolors (cf. http://linux.die.net/man/5/dir_colors )
	- icons (/etc/icons ? svg/hvif, setmime...)
	- Tracker usage bar colors
	- mouse cursors (needs app_server fixes ??)
	- Pulse colors (-> sample code)
	- BeIDE/Pe/Eddie full colors (map to singe namespace)
	- Vision/BeShare full colors (map to singe namespace)
	- Firefox theme ?