Google font directory singlets 1

This PR adds 471 OFL or Apache-licensed fonts from Google Web Font Directory.  These are all simple cases with a single TTF font artifact.

Each Cask is intentionally separated into a separate commit, to remain amenable to bisect, cherry-pick, etc.  However, setting up 471 PRs did not seem useful.

Further rounds will be needed before all of Google WFD is Casked.  However we now have well over half.