Commented useless newBackend code for new remote connection.
Added QUdpSocket to dcpserver, added socket argument to dcpserver* constructors.
Implemented DCPServer::sendPacket().
Added and implemented slot receiveDatagram() connected to sock in DCPServer.
Removed arg remoteType in DCPServerCommand::sayHello. It represent a command station therefore type is always remoteTypeCommandStation.
Refactored code in dcppackethandlerinterface.cpp (variable names, commands order).
DCPPacketHandlerInterface::backendSrv renamed to server.