Fixed erroneous query that was skipping signups for non-committee-chair senators.  Added --overwrite option, along with logic to prevent overwriting an already-existing spreadsheet.  Eliminated nysenate_emails[] array from return value of process_records(), since it is never used.  Added check to confirm that the count of retrieved signups matches the count of reported signups.  Added better logging output.
Merge branch 'dev' of github.com:nysenate/Bluebird-CRM into dev