Provide scripts for installing and running txircd standalone

Since Ashton asked about this, I wrote a few scripts to make running txircd standalone a bit more convenient. It handles setting up the virtualenv and provides an easy way to start and stop the deamon. It assumes python2-virtualenv, as well as the requirements for the dependencies txircd uses (these being a C compiler for Twisted, python2-dev, libssl-dev and libyaml-dev), are already installed on the system.
On most distros it is. I can't think of a better solution though. We COULD just point it to `usr/bin/python2.7`, assuming we'll say Python 2.7 is required.