Change attendees, speakers, and schedule to flatten sections before retrieving rows

Some calls were only returning partial results previosuly, as they were ignoring the way the iPhone client currently splits the reponse into different groups based on name or attendee type, for example.  The get_row call just takes the list of sections and collapses the rows together.  this applies to the attendees, speakers, and schedule method.

This should fix #5 for real this time.