Updated pollNode logic to handle how we number instances

This works on my single instance nodes where before the serial message generated was null and throwing an exception in sendData().  I don't have any multi instance nodes to test on however.  This functionality is mainly used by the HAIL and ApplicationStatus classes.  The change in ZwaveNode was not causing any issues, but I was assuming after looking through it that it should be using 1 as a starting point for instances instead of 0.