Renders the actual schedule on the conference schedule page.
Create talk slots inside a transaction
Improves rendering of schedule, with lunch, messages, and keynotes stretching across all 3 rooms.

Related updates to the schedule have been made live to the google doc.
Lightning talks are 3/20min, in 7/7/6 minute chunks.
Always yield a row, even if there are no slots. Produces a sparse layout, which I think is fine.
Add schedule.csv, more slot kinds.
Merge branch 'actual-schedule' into pyconca2013