[Cython] runtests libgomp fail

[mark florisson]

I added a test for nested parallelism with exceptions (with OpenMP
nesting explicitly enabled), however if libgomp cannot create more
threads it exits the process with exit status 1 and the message
"libgomp: Thread creation failed: Resource temporarily unavailable".
This then results in a red Hudson and I think it exits the testrunner
(are the tests not run as separate processes?). So what should I do?
Should I fork manually in my test and watch the exit status?

The result is here:
https://sage.math.washington.edu:8091/hudson/view/cython-mark/job/cython-mark-tests-py27-c/72/console