fixes crasher on OS X 10.5

filter and was resetting it.

PendingDeprecationWarnings to be spewed all over by unittest.failIf*(). Fix
moves over to using warnings.catch_warning to protect the warnings filter.

called in a thread that was spawned by an import itself.

Last part to close #1665206.

Dynamically discoverd the size of the ioinfo struct used by the crt for its file descriptors.  This should work across all flavors of the CRT.  Thanks to Amaury Forgeot d'Arc
Needs porting to 3.1

import lock if called from within a thread that was triggered by an import.

Partially fixes issue #1665206.

exactly one pattern, which avoids mysterious errors where it
had seemed to fail to do localization.

correction in a previously fixed test.

after closing the socket.