Implement a new csswring instance based API with per-instance  options.

  * `csswring({preserveHacks: true, removeAllComments: true}).wring(css, {map: true});`
  * `postcss().use(csswring({preserveHacks: true, removeAllComments: true}).processor).process(css, {map: true});`
  * `csswring.wring(css, opts);` now accepts `preserveHacks` and `removeAllComments` as options in addition to the postcss options.