Adding initial merge_target_files.py script to merge two target files packages.

  return subprocess.Popen(args, **kwargs)

def RunAndWait(args, verbose=None, **kwargs):

  """Runs the given command and returns the exit code.

  Args:

    args: The command represented as a list of strings.

    verbose: Whether the commands should be shown. Default to the global

        verbosity if unspecified.

    kwargs: Any additional args to be passed to subprocess.Popen(), such as env,

        stdin, etc. stdout and stderr will default to subprocess.PIPE and

        subprocess.STDOUT respectively unless caller specifies any of them.

  Returns:

    The process return code.

  """

  proc = Run(args, verbose=verbose, **kwargs)

  proc.wait()

  return proc.returncode

def RunAndCheckOutput(args, verbose=None, **kwargs):

  """Runs the given command and returns the output.