Get the mounttray working with the new XDG compatibility in libpcbsd.
When prompting to open an audio/video disk, it will now scan the system for audio/video application and let the user choose which one to start.
Clean up the new XDG *.desktop file usage. Now it will properly get text and only use the [desktop entry] section of a file.
Merge branch 'master' of github.com:pcbsd/pcbsd