While no copyright violation occurred, the license which
'Numerical Recipes' operates under is not amenable to Python,
so to prevent confusion it's easier to simply remove its mention.

Removed SSL_ERROR_SYSCALL checking from ssl_io_loop() so that the loop can
terminate when unwrap() raises that error.

This is instead of svn.python.org, whose certificate recently expired, and
whose new certificate uses a different root certificate.

The certificate used at the pythontest server was modifed to set the "basic
constraints" CA flag. This flag seems to be required for test_get_ca_certs_
capath() to work (in Python 3.4+).

Added the new self-signed certificate to capath with the following commands:

cp Lib/test/{selfsigned_pythontestdotnet.pem,capath/}
c_rehash -v Lib/test/capath/
c_rehash -v -old Lib/test/capath/
# Note the generated file names
cp Lib/test/capath/{selfsigned_pythontestdotnet.pem,0e4015b9.0}
mv Lib/test/capath/{selfsigned_pythontestdotnet.pem,ce7b8643.0}

The new server responds with "No route to host" when connecting to port 444.

Patch contributed by Swati Jaiswal.

Patch contributed by SilentGhost.

Patch contributed by Robert Zimmerman.

upstreams such as Cython will have to adjust.

  appearing before $() vars.

The decision is that we shouldn't remove popular APIs (however long they
are depreacted) from Python 3, while 2.7 is still around and supported.

picklability regression.  Also, as per further discussion, remove the
regressing code.