Move parts of setup.sh into Puppet

setup.sh was performing a lot of system setup activities. This patch
moves many of them to Puppet.

* Create to /repo and /repo_local directories
* Install the vcsrepo Puppet module to manage version controlled repos
* Clone the various repositories into their desired locations

In addition, since hghooks has been replaced by version-control-tools,
we clone version-control-tools and hook up mozhghooks from its new
home from there.