Rename dementors -> ocf_stats
Update apt module to 1.6.0
Update concat module to 1.1.1
Update nginx module to 0.1.1
Switch vcsrepo from my fork to latest HEAD

Back in August, I forked puppetlabs-vcsrepo to fix a bug with the dummy
provider:
https://github.com/chriskuehl/puppetlabs-vcsrepo/commit/a10626

Since then, they've actually incorporated a fix that is basically
equivalent to mine:
https://github.com/puppetlabs/puppetlabs-vcsrepo/commit/ead1aa

So, this switches back to the real puppetlabs-vcsrepo. They haven't
issued a release since the change, so I'm updating it to the latest
HEAD.