-- Added custom field support
Reworked the confirm, subscribe, unsubscribe, usersettings templates

** ON UPGRADE YOU MUST RESET YOUR FRONTEND TEMPLATES
NOTE: Previously existing templates for confirm, subscribe, unsubscribe, and usersettings actions are no longer compatible. For the purposes of data retention, existing templates are not erased on upgrade. You are responsible for copying all of your existing templates, pressing reset to factory defaults in each tab, and resetting the various templates to your liking.

NOTE: Message templates should remain compatible after the upgrade process and should not need adjustment.

-- Fixes to nms_image and nms_attachment plugins.