Add helper executables for interacting with the API

[Eeems]

• Make tarnish use a lock file to avoid multiple instances running at once
• [x] desktop-file-edit
• [x] desktop-file-install
• [x] desktop-file-validate
• [x] update-desktop-database
• [x] xdg-desktop-menu
  • [x] xdg-desktop-menu install
  • [x] xdg-desktop-menu uninstall
  • [x] xdg-desktop-menu forceupdate
• [x] xdg-desktop-icon
  • [x] xdg-desktop-icon install
  • [x] xdg-desktop-icon uninstall
• [x] xdg-open
• [x] xdg-icon-resource
  • [x] xdg-icon-resource install
  • [x] xdg-icon-resource uninstall
  • [x] xdg-icon-resource forceupdate
• [x] xdg-settings
  • [x] xdg-settings get
  • [x] xdg-settings check
  • [x] xdg-settings set
  • [x] xdg-settings --list
• [x] gio
  • [x] gio help
  • [x] gio version
  • [x] gio cat
  • [x] gio copy
  • [ ] gio info
  • [x] gio launch
  • [ ] gio list
  • [ ] gio mime
  • [x] gio mkdir
  • [ ] gio monitor
  • [ ] gio mount
  • [ ] gio move
  • [x] gio open
  • [x] gio rename
  • [x] gio remove
  • [ ] gio save
  • [ ] gio set
  • [ ] gio trash
  • [ ] gio tree