evaluate adding support for "ES2015" features via Babel

[Aeva]

I previously reviewed Babel for the compelling features it adds to the language, and quite liked it... except that the output code was particularly hideous. However, js-beautify seems to be more then capable at reflowing the output to being something I'd actually want someone to see! And you can control it either from just the command line or from within a python script!

So this ticket is simply changing the build process so it works like so:

• code gets assembled by CPP, as it does already
• CPP output is fed into Babel
• Babel output is fed into js-beautify
• js-beautify output is saved to mgrl.js
• put together a style guide for what is considered acceptable. Mainly the new function notation, binary literals, and string templates. Classes are definitely not ok (both because the implementation manipulates proto, and because classical inheritance in dynamically typed languages is just silly). Basically go through the new features provided and see what the output looks like.

[Aeva]

I think the main concern for this is, how many dependencies would get pulled in as a consequence, and how much of a nightmare this would make packaging >_>

[Aeva]

Ugh, so it looks like babel has about 32 dependencies. This might make it difficult to package M.GRL in other package managers, so I'm removing the 1.0 milestone requirement until I have a better idea of how this all works :P

[Aeva]

Erring towards 'no' for this, so closing the ticket for now.