add pingInterval same as used in ref C# implementation with the same logic
add pingTimeout which is used to check whether pong received. If not -- drop the peer.
add pingLimit which is hardcoded to 4 in TCPPeer. It's limit for unsuccessful ping/pong calls (where pong wasn't received in pingTimeout interval)
Our node didn't respect the MaxPeers setting, fix it with a drop of random
connection when this limit is reached (to give a chance for newcomers to
communicate), but also introduce AttemptConnPeers setting to tune the number
of attempted connections.
This also raises the default MaxPeers for testnet/mainnet to 100, because
neo-go nodes love making friends.
* Adds struct for config settings
* Bumps version
* Move settings around
* Only push version tag up not whole branch as well
* Move config into own path and add test and main nets
* Update config for timeouts
* Convert to yaml
