getaddrinfo takes an exclusive lock on some platforms, causing clients to queue
up waiting for the lock if many names are being resolved concurrently. Users
may want to handle name resolution in their own code, for the sake of caching,
using an alternate resolver, or to measure DNS duration separately from
connection duration. Skip getaddrinfo if the "host" passed into
create_connection is already resolved.

See https://github.com/python/asyncio/pull/302 for details.

Patch by A. Jesse Jiryu Davis.

In Python 2, these were duplicated; one for urllib.urlopen() and one for
urllib2.urlopen(). The test_urllibnet version has a better precondition to
avoid false failures with bad DNS, and the test_urllib2_localnet version had
a more up-to-date comment and domain name.

APIs into a note that mlsd() is a nicer API if the server supports
it.  They aren't deprecated, they are all different server commands.
Not all servers support all commands.

  parameter to "enable" the always on sys.flags.hash_randomization
  in _args_from_interpreter_flags() used by multiprocessing and
  some unittests.  This simplifies the code.
* assert_python_ok docstring typo fix.
* Fix test_cmd_line not to fail if PYTHONHASHSEED is set to a fixed seed.

parameter to "enable" the always on sys.flags.hash_randomization
in _args_from_interpreter_flags() used by multiprocessing and
some unittests.  This simplifies the code.

due to test_hash_randomization expecting a different seed per process.

This fixes a test failure in refleak mode because
test_property_decorator_doc_writable no longer modifies
the class in module level.

Initial patch by Nan Wu and Torsten Landschoff (from issue 25757)

See https://github.com/python/asyncio/pull/303 for details