improve event listing query when no end date set

when registering someone for an event administratively, we are given a dropdown with current/future events. however – the query to build that list defines current/future as events having a future end date or no end date.

the problem is that it's not uncommon for organizations to create a single day event using only the start date (start date is a required field; end date is not). as a result, events with no end date are listed in this dropdown – even if the start date was years earlier.

Dave –
I can provide a patch to improve the query, but want to run it by you first. basically, if no end date is set, we compare the start date to today's date in order to determine if it's current/future.