Some progress (sending side only)

Signed-off-by: Matthias Stevens <matthias.stevens@gmail.com>
Removed encryption code from (Records)Payload.
I'm getting more and more convinced this should be handled on the Transmission level. This also means any user idetification/authentication & encryption key determiniation should not depend on Projects/models (except maybe for default settings) but instead be related to client-sender/server-receiver pairs.

Signed-off-by: Matthias Stevens <matthias.stevens@gmail.com>
Minor stuff

Signed-off-by: Matthias Stevens <matthias.stevens@gmail.com>