Implement a new csswring instance based API with per-instance preserveHacks and removeAllComments 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.