Issue #16096: Fix several occurrences of potential signed integer overflow.  Thanks Serhiy Storchaka.

Patch by Serhiy Storchaka.

Patch by Serhiy Storchaka.

Closes #11710: create "landing pages" (/library/package.html) for those packages that have no documented content themselves, e.g. "urllib" or "http".

Issue #16115: Add test for check that executable arg to Popen() takes precedence over args[0] arg\n                            \n                            Patch by Kushal Das

MERGE: #16112: platform.architecture does not correctly escape argument to /usr/bin/file. Fix original patch

#16112: platform.architecture does not correctly escape argument to /usr/bin/file. Fix original patch

#16112: platform.architecture does not correctly escape argument to /usr/bin/file. Use 'communicate()' and decode the bytes

This error cannot occur in practice: PyUnicode_FromObject() always return
a "ready" string.

Thanks to Roger Serwy for patch.

Thanks to Roger Serwy for patch.

Issue #16089: Allow ElementTree.TreeBuilder to work again with a non-Element element_factory (fixes a regression in SimpleTAL).

Issue #12947: Better workaround for the problem with doctest directives being stripped from code examples that are intended to illustrate those directives