Sync up with upstream naming (`master`->`server`)

[jcpunk]

Upstream has switched a bunch of the settings from master to server for various parts of the puppet server. It would be nice if this module followed as I've no idea how long the old names will work.

[ekohl]

#770 was opened but never finished. Needs a non-trivial rebase now and I'll admit that I lack the time to work on it, but PRs are welcome.