Centralize Unicode and utf8 utilities to utils.py

![](http://25.media.tumblr.com/abaeeb7fa33a768caace00453a224d18/tumblr_muctp0pis21sqhdk6o1_400.gif)

* Tries to make `to_unicode` just get things into `unicode` type while `to_utf8` gets things into a `str` of utf-8 bytes.
* Don't think this is perfect, would love feedback.
* But it does pass all tests