Default ROM path for mame/mess

[Cesare Falco]

> http://anonscm.debian.org/gitweb/?p=pkg-games/mame.git;a=commit;h=ea304ff499877655877dd856a2e1d6692878d4cc
>
> I have no idea of why this happened in this commit, but I think it is bad
> enough to warrant a new upload.
that's always been the default in Ubuntu package, which in turn is
inherited from xmame IIRC.
I fixed what I thought was a typo.

I don't mind switching, but I'd like to keep all files in the same
subdirectory (i.e. from ~/.mame to ~/mame), I'm not very happy with
software spreading files around in my home directory. ;)

Users should also be warned if Mame stops searching ~/.mame/roms, or
they'll find their roms have "disappeared" and will probably start
complaining...

Cheers,
Cesare.