Write received data to disk
Write received data to disk

Received data is now written to disk in whatever directory we are in.
Can't handle multiple transactions currently. It is rather slow, because
every chunk is fully written to disk before the next chunk is being
processed. Old data is always overwritten.

PDXostc/rvi_sota_client,advancedtelematic/rvi_sota_client,advancedtelematic/rvi_sota_client,PDXostc/rvi_sota_client