alpha release, not suitable for production

Merge pull request moinwiki#603 from ThomasWaldmann/update-docs

docs updates

create moin/2.0 repo, drop all history (see notes below)

Up to now, we used the moin/2.0-dev repository (which was cloned from another,
older moin repo quite some time ago). Over the years, these repositories got
rather fat (>200MB) and were a pain to clone over slow, high-latency or
unreliable connections.

After having finished most of the dirty work in moin2, having killed all the
3rd party code we had bundled with (is now installed by quickinstall / pip /
setuptools), it is now a good time to get rid of the history (the history made
up most of the repository's size).

If you need to look at the history, look there:

http://hg.moinmo.in/moin/2.0-dev

The new moin/2.0 repository has the files as of this changesets:

http://hg.moinmo.in/moin/2.0-dev/rev/075132a755dc

The changeset hashes that link the repositories will be tagged (in both
repositories) as "moin20-repo-reboot".