Add comment field to match

Also add season filter to match edit
Fix bad call to $wpdb->prepare()
Fix to paging with season filter
Fix intermediate check for results
Update JS validation for matches
Fix typo
Ensure comment is included in admin display
Fix copy/paste bug
Fix bug in match data cleanup
Debug code for match save
More debugging
Fix bug in clean_match that prevents saving of matches
Clean up match handling
Fix null handling in new team save
Turn debug flag off and make configurable
Email UI, Member deletion and UI fixes

Multiple changes, including the following:
= Improve email UI to provide better feedback while waiting for sends
= Add API and button to delete members
= Create new common delete API (which indirectly fixed a bug in the
delete_match API)
= Fix layout issue in member trailing text
= Explicitly add off-white background to TeamData content