Fix up some issues causing exceptions and preventing emailing

The big issue was a debug statement not handling the hash being passed in, instead treating it as an array. After this was resolved I discovered the `remind?` method in the Issue patch was returning `nil` instead of `true` for one of the cases. I didn't trace everything through to see if this is strictly necessary, but it means the method returns a consistent binary `true`/`false` value instead of being a trinary result.

Finally this includes some cleanup of the HTML email - nothing major altered.