Adding a call/__call__ function to the operator module (where `operator.call(*args, **kwargs)(func) == func(*args, **kwargs)`, similarly to operator.methodcaller) seems consistent with the design with the rest of the operator module.

An actual use case I had for such an operator was collecting a bunch of callables in a list and wanting to dispatch them to concurrent.futures.Executor.map, i.e. something like `executor.map(operator.call, funcs)` (to get the parallelized version of `[func() for func in funcs]`).