MT#5879 Fix email template in customer edit.
MT#7493 API: Preserve int. prefs on update

Don't clear internal preferences when doing a PUT on preferences.
MT#7377 Fix pilot subscriber tagging.

Only set is_pbx_pilot on subscriber creation if there is no pilot yet.
MT#7555	Properly terminate subs on customer edit.

Recursively terminate subscribers and everything else if a customer
is terminated via the customer edit form.