add some version-identification of the package

[Former user]

it is useful to have some way to distinguish between diff. versions/builds/revisions - e.g. the svn's Rev, and maybe some version=...

e.g. sqlalichemy/init.py: revision = "$Rev$" version = '0.3.3'

[Mike Bayer]

id like setuptools to have some way to do this, i.e. to get the "version" number into the source code upon setup.py sdist. we've had some suggestions how this might be accomplished but nothing has been completed.

[Mike Bayer]

resolved, changeset:2747 changeset:2748