Align types: int to unsigned int

Block send SMS until finished operation.
GSM3IO.h. Keeps most of board-dependant pins
Flush buffer after GPRS detach
Delete some references to HardwareSerial.h
Include OFF modem status

libraries/GSM/src/GSM3MobileNetworkProvider.cpp

@@ -32,7 +32,6 @@ The latest version of this library can always be found at
 https://github.com/BlueVia/Official-Arduino
 */
 #include <GSM3MobileNetworkProvider.h>
-#include <HardwareSerial.h>
 
 GSM3MobileNetworkProvider* theProvider;