Add an OPTIONS entry that installs a .desktop entry for mozilla. I used the
contents of epiphany.desktop to generate the translations. I hope none of my
fellow GNOME Translation Project team members object to having their
translations bastardized like this. I don't know whether .desktop entries
can contain comments, so there's nothing attributing their work in there
I'll let this percolate in here for a bit, and if successful, I'll add it
to moz-devel, firefox, and thunderbird.