If MY_GATEWAY_CLIENT_MODE or MY_CONTROLLER_URL_ADDRESS are present, set
MY_GATEWAY_CLIENT_MODE.
MY_USE_UDP requires that MY_GATEWAY_CLIENT_MODE is set.
Add some ifdefs to filter some variables not needed in client mode.
Using global variables to keep the connection to controller open
therefore, no need to reconnect every time we need to send/receive
something.
Add the remaining code to handle incoming messages from controllers.
Marcelo Aquino
0c11354a2a