rlp.decode also returns strings
validate receiced peer addresses
read long packets
fix peer pings
fix send peers
don't connect yourself
exit if port is already used
added support for command line options
Use logger instead of `plog`

This replaces plog. In main() you see an example of how you
could use log-levels and the verbosity-flag from commandline.
return IPs as array of 4 bytes
merged
periodically ask for peers
Merge pull request #39 from brainbot-com/p2p_wire_rb

Improved Peer Handling, Commandline Options, Logger