🚜 Parsers: Make good support for Scroll/Parsers in Sublime Text

[breck7]

Implement correct scoping in sublime/textmate highlighters

• Currently we don't handle scoping correctly so the syntax highlighting for nested trees is often incorrect (but mostly correct since most nodes are on root)
• Should also have the ability to specify other modes, like "javascript" or "c++", for children, to leverage highlighters for other languages

Work for this is partially done at http://lime.treenotation.org/

[breck7]

This might be worth revisiting in ST4.

[breck7]

Closing in favor of this root issue: breck7/scroll#114