add tag 1.5b1 in github.com/django/django

[ido@…]

Now that 1.5b1 has been released, please git tag the commit corresponding to the 1.5b1 release and "git push --tags" so that it appears on github. I (and probably others) track the git repository and prefer to track well-known releases within the git repository rather than simply pulling from the master branch or stable/1.5.X branch at arbitrary points, which makes it easier to be explicit about which version I am using when reporting issues.

Also, add 1.5-beta-1 to the version list in trac.

If you have a release script, please adjust it to tag properly as well.

[Claude Paroz]

Done 4 hours ago.