Add option to stop execution if an app fails

[georgemccabe]

This would be useful if you are running a lot of times to be able to see where it failed so you can pick up where you left off. It would also be good for debugging development so you can clearly see when the first issue occurred.

The MET apps return 1 if failure and 0 if success. I believe we already catch this value in the METplus code. We would add a true/false config item (EXIT_ON_FAILURE?) and if true, check the return value and error/exit if the return code is not 0. Checking for not 0 instead of 1 should be used because John mentioned the possibility of changing the MET apps to have different number error codes based on the error.

I would have to look into it (or someone else can chime in) but I believe that most other applications return 0 on success, so we could use this functionality for non-MET apps as well. Some of them may expect to fail sometimes, so if that is the case, we can set a flag to tell METplus to ignore the error code even if EXIT_ON_FAILURE is set.

[georgemccabe]

This would be very easy to implement and would be useful for debugging purposes.