Improve the execute() method in edu.cmu.ri.createlab.serial.CreateLabSerialDeviceReturnValueCommandStrategy so that read failures cause a retry

```
Although we current retry writes, we don't retry if the read fails.  Change 
things so that a failed read (optionally?) causes a retry of the whole command.
```

Original issue reported on code.google.com by `garthabr...@gmail.com` on 14 Jan 2013 at 3:26
