Extend transaction timeout when new data is received

[whizzosoftware]

When WZWave starts a transaction, it sets the timeout to be an absolute number of seconds from the point that data is sent. There has been cases where seriously slow responses are partially received but the transaction times out before the complete response can be sent.

Ideally, the transaction timeout should be extended when partial data is received to compensate for slow data coming from the PC controller.

[whizzosoftware]

@anton-johansson: when you have a chance, could you try the code from branch issue-24 to see if you can reproduce the issue you reported in #18? The branch contains fixes for both #24 and #25. Thanks!

[anton-johansson]

I will take a look when I get home from work, later today!

[anton-johansson]

Okay, so I did some runs with the changes in branch issue-24. I did 7 runs, and exactly every other one gave no errors, while the rest gave errors:

1. No errors reported.
2. Some errors reported, see output.
3. No errors reported.
4. Errors reported, pretty much identical to errors in step 2, see output.
5. No errors reported.
6. Errors reported, similar to step 2 and 4, but not exactly, see output.
7. No errors reported.

[whizzosoftware]

Thanks for running the tests and providing logs. It looks like the transaction timeout extension code is doing what it should. I will need to dig into the other errors to see if they are related to this issue or not.