Add list of external subtrees to _config.yaml

This should be useful for the thing we'll use to update and link
subtrees into place? Also possibly for fixing edit links, although I
can't quite see the best way to do that yet because you can't use
regexes in a Liquid if tag.
Kill MCollective submodule and add externalsources directory to .gitignore

The idea here being that this and the puppetdb repo will be managed by the rake toolchain.
Blow away our copy of the puppetdb 1.1 manual

For great de-duplication.
Better data format for external sources in _config.yml

No need for multiple root-level keys -- each source can know what its
real upstream repo is, and we'll just handle de-duplication later.
First try at this new way of managing external docs -- see below for caveats

- Requires git-new-workdir be installed in the $PATH, which we'll have
  to change because it doesn't ship w/ git-core.
- No idea how it handles network failures.
- But it works!
Silence task descriptions of some non-user-facing tasks to chop down the list of tasks
All rake tasks MUST revert to their original CWD before ending or calling other tasks

I was seeing like three different failures revealed by this! Pretty
awesome. So new rule: Don't pollute the global state! Dir.chdir and the
equivalent FileUtils.cd may ONLY be called in their block forms, so that
the CWD reverts when the block is done. Much easier.
Switch to a captive copy of git-new-workdir for updating external sources

Because it doesn't ship with git-core, so no one has it. This script
came from the contrib dir of the git source.
Fix inability to clean symlinks more than once

Right, I forgot about Rake::Task#reenable. Remember that rake tasks fail
silently without warning if you try to invoke them a second time?
Neither did I.
Point puppetdb 1.1 docs at master until puppetdb team cuts a branch

We were pointing this at a tag for testing, but that's untenable in the
medium-term -- these docs must auto-update.
sanitize RUBYLIB of anything with /puppet/ in it. Too broad. Placeholder.
- Move to using bundler to handle gem installation and getting the right binaries.
- Clean rubylib of /puppet\/lib
- YARD docs added to list of generated references
progress on bundlerization
Progress on bundleification
README update to reflect new world order
Adding yard back to list of references
WIP: Adding new captives to gitignore, s/yard/developer
WIP: don't need a facter gem
WIP: .bundle not to be in VC
A number of changes to accommodate streamlined, bundler-based gem dependencies:

- jekyll now included in Gemfile from forked puppetlabs/jekyll version
  We're using a specific branch rolled back to Jekyll 0.11.2 that includes a small patch
  to include _index.html (to accommodate YARD) and symlinked directories (to accommodate our
  MCollective setup)

- system(jekyll) calls changed to `bundle exec jekyll`
  Some day, if we ever get to a point where stock Jekyll can accommodate our needs,
  we'll be able to point the Gemfile to mojombo/jekyll and carry on. This frees us from
  going into the Rakefile and repointing the location of the jekyll executable

- yard docs generation included (using "developer" in rake tasks, e.g.
  rake:references:puppetdoc:developer)