Release 0.9.4 just hit the net

Okay, that's it. No 500M$ unveiling event for this release of GiNaC, we're afraid, but you are still welcome to go out in the streets and deliver this message of joy to the masses: * Functions have better support for external scripting languages. * Interface cleanups and bugfixes. * Fix silly bug in evalf() that prevented things like 2^Pi being computed. Cheers -richy.