add debug flag to keep the results if there is a problem and also to print verbosely.
clarify names, check to make sure pipelines executed and returned results at all.
If system_call is called with a second argument, it should be a useful argument like a pointer to a log file handle.

And if a log file handle is passed in, then we don’t want the system
call to kill the whole process (because the call happened as part of a
different script).
Pass in the $log_fh when calling aTRAM so that the output ends up in the log.
Use the percentcoverage function directly instead of calling it on a separate process.
renamed test result files.