Added new datetime formats, found here: http://stackoverflow.com/questions/16798206/django-paypal-ipn-signals-not-being-received
Removed the validation of the transmitted receiver_email vs the RECEIVER_EMAIL in settings. This should only be a default, and prevents us from facilitating payments for others.
Fixed validation of the IPN form, utilizing this change: https://github.com/Jumpstartz/django-paypal/commit/eb1a875598f882e9f395a1ace963faefa6dfea1c#paypal/standard/ipn/views.py