tn version 14, can block ports, differential stat compression,
yet smaller binary again, due to separate compilation of keccak at -O2.
also use sha3 instead of fnv for file verification, with new enough
tns. this should further reduce risks of interference.
only do tn postinstallation after actual installation or rediscovery, not
on every connect, which speeds things up as well.
try to get rid of AnyEvent::Socket, unsuccessfully so far.