Closes#1192
1. We now have CMDGetBlockByIndex, so there's no need to request headers
first when we can just ask for blocks.
2. We don't ask for headers (i.e. we don't send CMDGetHeaders),
consequently, we shouldn't react on CMDHeaders.
3. But we still keep on reacting on CMDGetHeaders command as
there could be a node which needs headers.
It's bogus and no other node implementation has anything like that. It fires
up for no good reason in the case when some other node connects to us and it
obviously doesn't use its listening port for it.
* block partial persist
* replaced refactored files with old one.
* removed gokit/log from deps
* Tweaks to not overburden remote nodes with getheaders/getblocks
* Changed Transporter interface to not take the server as argument due to a cause of race warning from the compiler
* started server test suite
* more test + return errors from message handlers
* removed --race from build
* Little improvements.
* refactored tcp transport
* return errors on outgoing messages
* TCP transport should report its error after reading from connection
* handle error returned from peer transport
* bump version
* cleaned up error
* Set the listener of the server when opened.
* refactor server RPC.
* deleted proxy functions + moved TCPPeer to tcp file
* implemented the start of JSON-RPC
* changed string port args to int
* added peerCount.
* Start a server with startOpts
* Updated README
