IPN actually posts, not gets.
fixing parsing of parameters. fixing csrf exempt on return URLs (since paypal appears to be using POST commands :( )
Make adjustments to payment when IPN comes in.
Make adjustments to payment when IPN comes in.
adjust notification message to reflect already received payments.
handling of notification in the return string
fixed problem of first artist to be creating having issues with ID.  Payment listing shows payment ID, and artist is clickable.