[Twisted-Python] Try/catching yielded Exceptions and getting proper tracebacks

[Paul Goins]

Hi Terry,

> You're only printing the exception, not a full traceback, so you don't see
> much. I tend to write what you're doing as follows: [...]

Excellent.  I'll give it a try.  I had a feeling it was something like
that which I was missing.

I already understood that inlineCallbacks returns Deferreds, but the
clarification is appreciated nonetheless.  I think it was just my lack
of understanding of how Failures are handled, logged, etc.

- Paul