Get the PDFs out of the git repo

Binary blobs in the repo are bad news, and we're already paying the price.
(← my bad.) Instead, since we report the commit sha on the front pages of the
PDFs themselves, we can use THAT to get the list of new files since the last update.
Fix a dead line in the puppet 3 nav
Turn on the complete example link in the Hiera nav
Update PDF instructions and rake tasks to account for the new external sources model
Add many new PDF targets, update a few

- Add deployment guide
- Add PE 2.8 user's guide
- Add PuppetDB 1.1 and 1.2
- Add complete example and lookup types to Hiera
- Add "what's new", lang_experimental, external CA, report format, and agent/master HTTPS to Puppet 3
- Add release notes to puppet 2.7
- Add Facter 1.7 and 1.6 core facts
Fix broken PDF rake tasks

- That ../ problem.
- Sitemap generator hates me.
Fix some links in console cert mgmt guide for PE 2.7 and 2.8