* README.md - update description of the `emojify_tag_type` option, it is
  now used to determine if emojify should replace elements with img
  elements OR the value set in `emojify_tag_type`

* Gruntfile.js - use promises for buildCSS task

* emojify.js - Update code for `emojify_tag_type`

* emojify.css/emojify.min.css - Comitted generated CSS

* package.json  - Add grunt-contrib-cssmin and q