Initial work on CSV attendee view.
Merge branch 'master' into csv_exporter
Abstracted CSV export heavy-lifting to its own class.
Abstracted fields in the CSV exporters a bit.
Expose data exporter to HTML.
Made fields for CSV export customizable.
Added a million fields to the AttendeeCSVExporter
Fix modal header.
Serve CSVs with the proper mime.
Added comma_separated_manager to __all__.
Removed extraneous imports.
Merge branch 'csv_exporter'