Add sabertooth lib, start enabling all motor drive

lib/Sabertooth/examples/2.Settings/SerialTimeout/SerialTimeout.ino

@@ -0,0 +1,33 @@
+// Set Serial Timeout Sample for Packet Serial
+// Copyright (c) 2012 Dimension Engineering LLC
+// See license.txt for license details.
+
+#include <Sabertooth.h>
+
+Sabertooth ST(128);
+
+void setup()
+{
+  SabertoothTXPinSerial.begin(9600);
+  ST.autobaud();
+  
+  // setTimeout rounds up to the nearest 100 milliseconds, so this 950 will actually be 1 second.
+  // A value of 0 disables the serial timeout.
+  ST.setTimeout(950);
+}
+
+void loop()
+{
+  // Set motor 1 to reverse 20 (out of 127), and sleep for 5 seconds.
+  // Notice how it cuts out after 1 second -- this is the serial timeout in action.
+  // Since we configured it in setup() for 1 second, 1 second without any new
+  // commands will cause the motors to stop.
+  ST.motor(1, -20);
+  delay(5000);
+  
+  // Why do this?
+  // If the S1 wire gets cut for some reason, or if your program crashes,
+  // the Sabertooth will stop receiving commands from the Arduino.
+  // With a timeout, your robot will stop. So, it's a safety feature mostly.
+}
+