refactor(HTTPError): Rename "raw" method to "dict"
chore(CONTRIBUTING): Inline Angular.js commit style guide

Rather than make readers hop somewhere else, inline the commit style
information to make it more convenient and obvious what is expected.

Also polish up the introductory text and code style requirements to
reduce confusion.
Merge pull request #347 from kgriffs/rename-raw

refactor(HTTPError): Rename "raw" method to "dict"
Merge pull request #348 from kgriffs/chore

chore(CONTRIBUTING): Inline Angular.js commit style guide