Proposed CRM-11801 configurable Authorize'net receipts

This causes Authorize.net to respect the clients configured preferences
for whether a receipt should be sent out.
Proposed (not in core) allow cancel of duff subscriptions

R3322 Recurring Contributions without contributions are not cancellable on the
relevant contact summary tab (due to SQL join)

Conflicts:
	CRM/Contribute/BAO/ContributionRecur.php
Proposed (no JIRA) Allow remote pdfs in receipts

This has been discussed in forum but AFAIK no action taken on it. This
makes PDF images work with full URLS
 CRM-12679 Fix Paypal Express Recurring IPN not working ...

Record Paypal express ipn contributions from recurring
Proposed - log all IPN calls - Fuzion only at this stage