Investigate methods for translating strings in Unixoid shell scripts

Once the fix for #2824 (closed) is merged, Tor Browser Bundle for Linux will be able to display error messages to non-technical users. Someday, we may need to have these error messages translated.

We need a solution that is either (a) pre-installed on Debian Squeeze with the default X Window System setup and installed on FreeBSD systems with GNOME or KDE installed, or (b) small enough to ship in the TBB for Linux tarball. Perl and Python programs are currently not acceptable unless they are very likely to be pre-installed on users' systems.