[mythtv] unprivileged user?

[Chris Petersen]

> What mythtv user?  Most systems with mythtv installed probably don't have
> such a user.

Thus, you create it.

ok, basically, you can specify the userid during compile (defaults to
"mythtv"), and override this on startup with a --username type flag.  If
such a user does not exist, myth could either create the user for itself
(not such a good idea - though it might be fine as an optional command
line argument), or exit with an error message explaining that an
unprivileged user named X needs to exist.  User creation can happen
automatically for those of us who use packages.

Anyway, it's not really a big deal - just thought that it'd be a nice
security enhancement.

-Chris