Closes issue #21209.

This makes doctest work like unittest: if the test case is empty, that
just means there are zero tests run, it's not an error.  The existing
behavior was broken, since it only gave an error if there were *no*
docstrings, and zero tests run if there were docstrings but none of them
contained tests.  So this makes it self-consistent as well.

Patch by Glenn Jones.

Normally an SMTP server will return an error, and smtplib will then issue an
RSET to return the connection to the known starting state.  Some servers,
however, disconnect after issuing certain errors.  When we issue the RSET,
this would result in raising an SMTPServerDisconnected error, *instead* of
returning the error code the user of the library was expecting.  This fix
makes the internal RSET calls ignore the disconnection so that the error code
is returned.  The user of the library will then get the SMTPServerDisconnected
error the next time they try to talk to the server.

Patch by Kushal Das.

Convert urllib.request parse_proxy doctests to unittests.

Fixes issue20307.  No Misc/NEWS entry because frankly this is an
esoteric platform for anyone to be figuring out how to cross compile
CPython for.

Fixes issue20307.  No Misc/NEWS entry because frankly this is an
esoteric platform for anyone to be figuring out how to cross compile
CPython for.

#10481: describe universal_newlines' effect on communicate()/check_output() output (alternately bytes or strings)

Patch by Sam Kimbrel.

Patch by Sam Lucidi.

Original patch by Caelyn McAulay; modified after discussion w/ her at
the PyCon 2014 sprints.

Issue #7776: Fix ``Host:'' header and reconnection when using  http.client.HTTPConnection.set_tunnel()
Patch by Nikolaus Rath.

Issue #7776: Fix ``Host:'' header and reconnection when using http.client.HTTPConnection.set_tunnel().

Patch by Nikolaus Rath.