bugfixes and optimizations

The original script did not work for me due to several bugs, for example spaces in author names, spaces in filenames, issues with `sed` on a Mac, and others. I fixed them and did some more cleaning up and optimizations.

Btw I renamed the project (on my github acct) to `gource-live`, as the idea can be generalized to work with other repo types. I generalized the scripts, implemented a Python wrapper with command line parsing, and added feeder scripts for Bazaar and Subversion.