Provide Imports and Require variable names

[F1LT3R]

Added ability to get names of imports:

import {foo, bar, qux as fizz} from 'baz'

..yeilds...

 result = {
  expressions: [],
  strings: ['baz'],
  imports: {
    baz: ['foo', 'bar', 'qux']
  }
}

... and so-on.