to stderr during the test run and it happened to get emitted after the
worker thread emitted the result JSON.  Now we capture stdout and stderr
separately, which avoids that problem.  It also means that _all_ stderr
output is after all stdout output when we print the test results, but
that seems acceptable, since output ordering is not guaranteed anyway.
The patch also moves the emit of the test name into the output block
generated after the test completes.  Otherwise test names and test
output/errors were mixed in the terminal display, making it difficult
to determine which test generated the output.

trying to detect proxy settings on OSX.

Using CleanImport to revert a reload of the os module doesn't work due to function registrations in copy_reg. The perils of reloading modules even for tests...

Also check and restore identity of sys.path, sys.argv and os.environ rather than just their values (this picked up a few more misbehaving tests)

Don't invoke reload(sys) and use StringIO objects instead of real files to capture stdin and stdout when needed (ensures all sys attributes remain unmodified after test_xmlrpc runs)

Enhancement to the new environment checking code to print the changed items under -vv. Also includes a small tweak to allow underscores in the names of resources.

an obscure, undocumentated feature so no test was added. Closes
issue #1101399.