Things to do:
  * Clean up the code. It's a bit messy.
  * Add user switching support for obsession-exit.
  * Obsession-logout and obsession-exit have some code in common. Share it in a new file.
  * Comment the code.
  * Take a look a LXDE git for changes since the last lxsession release.
  * Rewrite some tools in vala ? (done for xdg-autostart)
  * ideas ?
  