[Reviewer Andy] Fixes #569 - Add extra context to error logs for HSSConnection

Andy

Can you review my updates to Sprout's HSSConnection class to add context to the error logs.  I was finding it was impossible to correlate these errors to SAS output because the logs didn't have any context and I decided it would also make sense to ensure the bodies sent and received were logged as well, which required a bit of restructuring.

Mike