Added Hale tutorial, updated README

Summary of Changes:
Added a Tutorial

Cleaned json in spec
Rewrote section on render
Now supports "enctype" and "request_encoding" as two separate fields
Changed "enctype" default
Cleaned up text for "options"
Well, I could go two ways on this:

1. First section gives a light overview of everything, including how _meta can be used to DRY things.
2. Show just a sample at the beginning without advanced functionality and just cover that in appropriate section (line 427 etc).

I think we should probably go with option 2 and lighten up this front example (e.g. get rid of the interpreted as and just have one example). _meta advanced is a bit of a WTF for the casual viewer so probably better to lead them more progressively? Concur? If so, lets just clean up one overview example that could be pretty light to intro most of the tractable stuff.