Replace PUC with a BOR command and include dummy command to blush buffer

[Arthi Bhat]

Currently, the Python code initiates a PUC by setting an invalid Watch Dog Timer password. A better solution is to do a BOR which would reset all registers back to its default value before the user application starts. This way, when the user application starts, it behaves exactly how a standard power-up would behave for the customer.

A PUC may also get a customer into trouble if the customer has some code routine in their start-up that checks what caused a RESET. And, if their routine catches a false WDT password (due to a PUC), their routine may catch and thus making it difficult to debug why their device is catching a WDT password violation.

Also a dummy command needs to be included after the reset occurs. RAM_BSL files greated thatn .06 requires the host to send a read command, a CRC, a write command or a reset command to a new location in order to trigger a buffer flush. BSL buffers all data until a 128 byte block is received and then writes the data to device. If an image did not end on a block boundary the data is not transferred tot he device.

Python code updated with the two changes in bsl5.py.