Only send a SYN|ACK packet after Tor connection succeeds
- Switch our version of smoltcp to a fork with one small patch applied
1 that lets you withhold sending SYN|ACK packets with a new
pause_synack
function. - Use it to only send SYN|ACK after we successfully connect on the Tor side of things. This way, we send back a proper RST packet if the connection failed, instead of establishing it and immediately aborting it.
Closes #74 (closed).