Updated settings

Ports specified in -port and -rpcport options are now validated at startup. Values that previously worked and were considered valid can now result in errors.

P2P

UNIX domain sockets can now be used for proxy connections. Set -onion or -proxy to the local socket path with the prefix unix: (e.g. -onion=unix:/home/me/torsocket).
UNIX socket paths are now accepted for -zmqpubrawblock and -zmqpubrawtx with the format -zmqpubrawtx=unix:/path/to/file.