added synchronized on configs set when loading device config files
added getDeviceConfig() function to SerialControl class
added lines to init() in DeviceConfig class to load addresses from device config files
added getAddresses() function to DeviceConfig class to clone a snapshot of known addresses
added idEquals() function to DeviceConfig class
commented unused set command
added getPlugin() function to Connection classes
added LINE_ENDING constant and minor formatting change in ConnectionSerial class
added ArduinoDevice class for SerialControl protocol
replaced ArduinoGC with new SerialControl plugin in pom and package files