Display sessions and sponsors by event
New menu : "Infos/Mix-IT 2012". Displays talks, speakers, and lightning talks.
Hide menus not yet used
Label for no speaker to be displayed
Fixed SQL migration scripts
Fixed Java version to 1.6 to ensure CloudBees deployment.
Sponsor : call for sponsoring. Refactored page.
Use Member.ticketingRegistered=true before resetting to add "Attendee 2012" badge (even if a badge bug didn't give them a "Attendee badge").

Fixed SQL
Merge pull request #139 from clacote/older-events-display

Older events display