Update wsgiref for PEP 3333, and fix errors introduced into the test suite by converting type() checks to isinstance().
(When WSGI specifies a built-in type, it does NOT mean "this type or a subclass" -- it means 'type(x) is SpecifiedType'.)

Closes issue #10294. Thanks Stefan Behnel for the find.

Updating unittest docs to reflect change in unittest.TestCase.assert[Not]AlmostEqual signature change

# I don't have this compiler, so I couldn't test it.

Remove the keyword only restriction for places and delta args in unittest.TestCase.assert[Not]AlmostEqual

Fix for issue 9355 where with multiple mutually exclusive arguments, some brackets were being lost in the usage messages

Use a context manager for os.popen and explicitly close a socket.