Add list of provisional events to home page

[gvwilson]

Add list of provisional events to home page

[rbeagrie]

Happy to look at this one too.

I guess the simplest approach would be to add null=True to the Events.start field. In this case it might be worth allowing null values in the Events.admin_fee field as well - so that someone could create a new provisional workshop before necessarily knowing what the fee should be.

My only worry with doing anything that would alter the data model is that I don't understand what migrater.py and db.sql are doing. Is db.sql essentially just to fill the database with some values so that people can hack on the code? If so it might be better translated into a yaml or json fixture so that it would be a) a little more robust to data model changes in the future and b) independent of any specific database backend.

[gvwilson]

I'm not sure how to handle upcoming events (as you say, the model may
require changes). How about tackling #9 instead? I believe Django
supports pagination.