Little fixes in peer network.
(1) Use of unsigned port number
(2) Fix of copy pasta error in window isLocal logic
(3) On outgoing connection print endpoint instead of peer.endpoint
 (this fixes 0.0.0.0 appearing in log on OSX as not fully initialised)
Fix up IP port number to be ushort where it is used instead of short.
Wrote useful help output for -h,--help
Merge branch 'serverhelp' of https://github.com/csibbitt/cpp-ethereum into serverhelp