Rewrite the entire module :O

As per an email I sent to sdague earlier today, I have started re-writing the entire module as I'm trying to get the functionality rolled into groups.drupal.org and the mapping of fields via the theme system isn't ideal for that scenario, as well as the fact that the defaults will need to be overridable by the user posting the event as each group would have a different meetup.com group, and some groups contain multiple groups (Country with Regions, etc).

Attached is the first pass, I haven't been able to do a huge amount of testing yet as I haven't yet got a way to do so without spamming my meetup.com groups, but the only major pending changes are:
- Venues AJAX/AHAH functionality needs to be implemented so that when you choose a different group the available venues for that group are loaded.
- Override defaults should be stored on the user account so that each time they create a new event the defaults are set for them.

I'm sure there's more, but I just wanted to get something online so I had a issue to track updates and testing against.

Patch coming in first comment.