emailer_create

Max date picked up initially instead of in a sub-query
Added new delete query for nonsense emails.
emailer_edit

Added delete all checkbox and associated javascript for selecting /
unselecting all the checkboxes to mark for deletion.
emailer_send

Have set min no of days between emails to 7 days.

Added code to delete all those emails that were not sent due to various
reasons (missing matching product in JOINED tables etc