On CUDA error, print debugging information

[PhilMiller]

What Needs to be Done?

In AsyncOpCUDA, the abort message when an error is detected on a stream is completely uninformative. It should print

1. The error value and its description
2. The stream identity
3. The event identity

To support doing this with low overhead, move from vtAbortIf to testing the condition with if, and constructing an error string and calling vtAbort

[PhilMiller]

The stream identity isn't actually saved in the event, so it would add overhead to try to print that. I'll add the event, and if necessary, a debug print could be added to correlate events with streams.