make an autocomplete-plus provider for supercollider

[crucialfelix]

Possibly this should be a separate package, or maybe even somebody else could do this.

https://github.com/saschagehlich/autocomplete-plus/wiki/Tutorial:-Registering-and-creating-a-suggestion-provider

Build an index of class and method names from the currently configured supercollider library + quarks. This could be saved as as JSON file file so it could be used also by sublime, emacs, vim etc.

[crucialfelix]

https://github.com/atom/autocomplete-plus/wiki/Provider-API