a workaround to Tix library bug.

Issue #27989: Tweak inspect.formatannotation() to improve pydoc rendering of function annotations. Ivan L.

Patch by Piotr Szczepaniak.

* Use context manager on urllib objects to ensure that they are closed on error
* Use self.addCleanup() to cleanup resources even if a test is interrupted
  with CTRL+c

This backports a patch by Victor Stinner.

Initial patch by Hans Lawrenz.

Patch by Johannes Ebke.

Thanks to Ville Skyttä for the patch.

Patch by Vajrasky Kok.

Patch written by Julien Palard.

loss in PyTraceBack_Here().

Reported by Sam Lunt on docs@p.o.

Patch by Mariatta Wijaya.

Patch from Xiang Zhang.

Patch by Xiang Zhang.