Provides a subclass of Thread with facilities to raise an exception
in the thread or terminate the thread from another thread.

terminable_thread provides a subclass of threading.Thread, adding
the facility to raise exceptions in the context of the given thread.

This facility is incorporated in the terminable_thread.Thread methods
raise_exc, which raises an arbitrary exception, and terminate, which
raises SystemExit.

This is not done in an entirely robust manner, and there may be
unreported issues with it.

It uses the unexposed PyThreadState_SetAsyncExc function (via ctypes)
to raise an exception for the given thread.

WWW: http://github.com/intuited/terminable_thread