Utilities: Add a helper script for doing a bunch of canonical links at once

This is the second or third time I've needed something like this. I lost the
tools I used last time, and they ultra-sucked anyway, but this one's sort of
okay so maybe next time I can save myself some frustration.
Guts: Allow duplicate external repos from GitHub users other than puppetlabs

Since we were naïvely using short names for the main repository directories, we
hit a collision when I tried to include a branch from my own fork of the
mcollective repo. This commit cleans the full git URL to make main repo
directory names, so duplicates from different users will be unique.

NOTE that if you have ever generated the site before, you will need to delete
the contents of your puppet-docs/externalsources directory before generating it
again.
Add old mcollective menu based on commit c46ac41ed10deb97935aa7a886e739d58ceebd9b

This was the last version of this menu that could accommodate the Mco docs as of
version 1.2.1.
Fix paths in mco 1.2 nav for new directory
Add old version warning to mco 1.2 nav sidebar
Add mco 1.2 external source and nav snippet to _config.yml

And rename the main MCollective source.
Remove pages that didn't exist yet from the Mco 1.2 sidebar navigation; change one URL
Merge branch 'ancient_mco'