Log all PayPal IPN messages in Gateway Log
The PayPal gateway module should log all IPN messages in the gateway log, even if they're not supported.
Currently the PayPal module will only log certain IPN messages in the gateway log - these are payments, refunds and a few more. There is a category/error type for 'Not Supported', however only subscription errors are included here - dispute/chargeback IPN messages are completely ignored.
Logging all IPN messages, regardless of whether they're supported to the gateway log will allow developers to create hooks to perform actions when unsupported IPN messages are received - since some aren't logged, it's impossible to perform any action on these.