IRCContact consume 2 events:

    ('builders', None, 'builds', None, 'new') => A build is started
    ('builders', None, 'builds', None, 'finished') => A build is finished

When we will be able to get the list of changes for a build, the IRCContact must be updated.
Fix sa2ajj's comment
Merge pull request #1335 from delanne/IRCContact

IRCContact use the DATA API