Bug #55: Add API for IRC data
Proposal IDs are ints

* emphasize in doc that proposal IDs are ints
* only return the 4 documented fields from get_irc_logs
Merge branch 'feature/55-irc-data' into develop
Merge branch 'develop' of github.com:caktus/pycon into develop
Fixing sponsorship button on homepage.
Merge branch 'develop' into staging