[PATCH 0 of 3] tarballs and documentation

[Thomas Arendsen Hein]

Now tarballs can be created using 'make dist'.
Maybe the documentation generation should be moved to setup.py later,
because otherwise the tarball won't include the man and html pages, if
someone manually calls 'setup.py sdist'.

The release process now should be:
tag a release
hg update -C TAG
make dist

This will create dist/mercurial-TAG.tar.gz