FAZ entry point.

def faz(input_file, variables=None):
    """
    FAZ entry point.
    """
    logging.debug("input file:\n {0}\n".format(input_file))
    tasks = parse_input_file(input_file, variables=variables)
    print("Found {0} tasks.".format(len(tasks)))
    graph = DependencyGraph(tasks)
    graph.show_tasks()
    graph.execute()