Merge pull request #1 from jwhitlock/packaging

Add setup.py and other packaging nice-to-haves
Merge pull request #2 from jwhitlock/content_type

Set content type to application/vnd.api+json
Fix docs and email
Remove `setup.py test`

This ended up causing issues with readthedocs, and I would rather
not package py.test this way.
More docs fixes
Handle 400 Bad Requests w/ JSON API Error format
Add status code to error representation
Flatten 400 errors
Convert to JSON Patch-like error format