Upgrade causes loss of all firefox settings (?)

[Ralf Mardorf]

The profile should be available by 'firefox -ProfileManager' [1], OTOH
I'm booted to Ubuntu Precise and the ProfileManager doesn't start, for
Arch Linux I used two profiles, one shared with another Linux and after
a while I couldn't use the shared profiles anymore, but the
ProfileManger still started.

In the past
rm -fr nh2ykiym.default
mv 4up9dkb1.default nh2ykiym.default
worked, or instead simply chose it with the ProfileManger, but nowadays
there might be something fishy.

[1] IIRC only one could have the name "*.default", the other must have
another name, *.foo.