GIT v0.99.4

Thanks a lot to everybody who sent in usability enhancements and
bugfixes.

Updates since v0.99.3:

- HTTP transport can pull from a packed repository.
- RPM and Debian packages are hopefully usable out of the box.
- Read-only operations on read-only repository should work better.
- Commit and tag takes the message from the command line with -m.
- Shortlog does not show things in reverse anymore.
- Many commands now natively know SHA1 expressions (e.g. HEAD^^2).
- Push can update remote refs that have different names from local.
- Comes with the latest gitk.
- A new command "git revert"
- A bulk e-mailer (not installed by default).
- Hopefully less leaky and less buggy.