Make string scopes follow well known conventions

http://manual.macromates.com/en/language_grammars#naming_conventions
Make symbol to be constant.other.symbol.julia

This matches Ruby naming conventions.
Add a license

This is the same MIT license used by https://github.com/nanoant/DisableTurboBoost.kext.
Merge pull request #2 from aroben/patch-1

Add a MIT license
Add original authors to LICENSE & add it to README
Use explicit count modifiers

The `{,N}` extension is not supported by most Regexp engines, as it is
an Onigurma-only extension.