Log Message:
net/py-magic-wormhole-mailbox-server: import py-magic-wormhole-mailbox-server-0.4.1

This repository holds the code for the main server that Magic-Wormhole
clients connect to. The server performs store-and-forward delivery
for small key-exchange and control messages. Bulk data is sent over
a direct TCP connection, or through a transit-relay.

Clients connect with WebSockets, for low-latency delivery in the
happy case where both clients are attached at the same time. Message
are stored to enable non-simultaneous clients to make forward
progress. The server uses a small SQLite database for persistence
(and clients will reconnect automatically, allowing the server to
be rebooted without losing state). An optional "usage DB" tracks
historical activity for status monitoring and operational maintenance.