XF2 Addons What's New Digest 5.3.1

Sends daily, weekly or monthly emails containing highlights of what's new

Minor change for XF2.2 backwards compatibility. Only required if running XF2.2 - anyone running XF2.3 can skip this upgrade if you choose.

• update helper_account template modification to work with both XF2.3 and earlier versions
• listen for sparkpostmail_non_transactional_stop_map event and use the whatsnewdigest email stopper
• tweak unsubscribe confirmation message
• separate out getMail function so we can over-ride it and add functionality