Bug#618376: gnome-session: After updating to gnome3 file:// links aren't opening with the correct program

[Jeremy Bicha]

I fixed this in Ubuntu with this edit (we're still using the
desktop-file-utils package to set default mimetypes)

http://bazaar.launchpad.net/~ubuntu-branches/ubuntu/oneiric/desktop-file-utils/oneiric/revision/43