[Final] Isaac's Optimal Font Size Stuff So Far

I finally figured out how to isolate a range of commits so that we can use just his code--even though he's starting from a different base-branch.  For future reference, use "git cherry-pick" with a range of commits.  :octocat:

We're really the first ones to test this code, and it's still far from perfect.  But it's good enough that we can use it to find the right font size to fit text into reasonably-sized boxes... with a little fudging on the Lua side.  Next on the list is getting it to work with ```setGlyphScale()``` so that we can do non-blurry text on devices with a ```contentScale``` greater than 1.0.  :eyes: 

If you merge https://github.com/mindsnacks/Ahu/pull/54 into Ahu, you can actually use this stuff.  :smile: