fixed an error within the error processing that happens when contextio returns an embedded error instead of a top level error. yes, confusing.
some request errors don't have 'messages' in the body
Update __init__.py
added support for list_headers and facebook_headers
Bumped version number to 2.x because this is for V2 API, and to 2.0.1 for my changes
Merge pull request #3 from Tengah/master

Fixed error handling and added support for list_headers and facebook_headers