Fix for issue 10684: Folders get deleted when trying to change case with shutil.move (case insensitive file systems only)

Issue #11647: allow contextmanager objects to be used as decorators as described in the docs. Initial patch by Ysj Ray.

interpreter is shutting down; instead, these threads are now killed when
they try to take the GIL.

interpreter is shutting down; instead, these threads are now killed when
they try to take the GIL.