No functional change.
VPINs are unsigned integers in the range 0-65535 (although the highest values are special, 65535=VPIN_NONE). Values above 32767 were erroneously being displayed as negative. This has been fixed, which is a pre-requisite for allowing VPINs above 32767 to be used.
Update I2C addresses of HAL devices to type I2CAddress (to support extended address functions).
Cast I2CAddress variables in DIAG calls to (int).
Remove uses of max() function (not available on some platforms.
Performance enhancements in IODevice::loop() function.
Improved error handling, device is placed off line if not responding.
Improved error reporting, device shown as offline if not operational (faulty or not present).
