Metadata less

Dale,

here is the metadata-less version of gitfiletree.

To summarize the features:
* It's not reading the monticello.meta/version file anymore,
* package version info is extracted from the git commit ID choosen (author, time stamp, message),
* package ancestry is rebuilt from the package-related commits and the full repository log history,
* package version numbers are extracted from the list of package-related commits,
* package id is randomly created everytime the repository filenames are loaded,
* all tests are green on my system and pharo2.0,
* no changes to the package writing code, it is the filetree code.

It does change the way the repository contents look like (particularly history, version numbers and author), so if you can validate the way it looks (or if others may have a look as well), I'd be happy to have your return.