Pax TCP connected device may time out. when that happened, the client remained set but stream was not, which would result in the subsequent calls to the API failing with NullPointerException. Only solution was to create a new Device for each transaction.

This adds a catch around the potential connection timeout to reset the client, allowing the Device to be saved and reused for multiple transactions.

This also adds some minimal thread support, so that if Cancel is called while it is waiting to connect, it throws a meaningful error instead of a NullPointerException.

The PAX D190 is mobile and shuts off frequently, and doesn't accept connections, making these issues important for supporting the D190.