Station App Refactor [gitlab]

Solve the following problems:

[ ] Periodic logging about number of registrations seen, valid, expired. number of session active and bytes transferred.
[ ] when logging expired registrations log all seen (and all missed) registration decoys
[ ] Centralize session tracking around session ID (derived from shared secret) instead of phantom IP
[ ] Stop using shared secret for deriving everything, start using session ID or other identifier created using HKDF

This will almost certainly require a re-architecting of the structures that store and operate on session information.

original submission: 1/16/2020

refraction-networking / conjure