Basic mentions support
Create post authorization spec WIP
Create credentials post when creating app registration post and link to it in response link header
Add authorize-type-uri format validator (uri or 'all')
Create credentials post when creating app-auth post and link to it in response link header
Refactor: split content types from mime types
Misc fixes to get specs passing (meta post related)
Fix server entity in spec
be_success doesn't take failure message param
Response status is 404 by default