I propose to mark as deprecated the parameters `ignore_errors` and `onerror` of `shutil.rmtree()`, and raise a warning if used.

The reason is I feel them unpythonic. For emulating `ignore_errors=True`, the code can be written simply with a `try-except` that passes by default all `OSError`s . The `ignore_errors=True, onerror=myHandler` case can written simply with a `try-except` that handles `OSError`s. And in the handle can be code or a call to an handler with the same paramaters `myHandler` accept.