Configuring Gitweb for Apache on Debian

[git.ithinksw.org](http://git.ithinksw.org/) is a pretty nifty site: in addition to providing Gitweb when you access it via a web browser, it also allows cloning of repositories in the same namespace. So, for example, you can visit [http://git.ithinksw.org/ITFoundation.git](http://git.ithinksw.org/ITFoundation.git), and receive a Gitweb-generated interface to the repository, but you can also run `git clone http://git.ithinksw.org/ITFoundation.git` to clone the repository. [tycho](http://tychoish.com/) is also a fan of Git, and was interested in setting a similar site up for his own repositories, so I've decided to share my configuration here.