Autoinstallers should use svn co instead of untar

[geofft]

Most of our software supports upgrading by switching to a newer tag, updating, and possibly running an upgrade databases script. If we install a SVN (or whatever VCS) working copy rather than extracting a tarball, users can upgrade their own installs easily. Our auto-upgrade process should also become easier.

For SVN, we can merely generate a tarball with the .svn directories and keep our existing auto-install (and to some extent, auto-upgrade) infrastructure. I suspect this will work with all other VCSes.

There are also packages such as Django that very much recommend installing HEAD rather than a tarballed release, so having an infrastructure that will deal with VCSes will make it easier to support such packages.

[ezyang]

The decision was to use a Git based system, named Wizard.