Fix forking in runtests.py (ticket #449).
Fix forking in runtests.py (ticket #449).

hpfem/cython,JelleZijlstra/cython,hickford/cython,JelleZijlstra/cython,cython/cython,mcanthony/cython,rguillebert/CythonCTypesBackend,madjar/cython,hpfem/cython,larsmans/cython,da-woods/cython,mrGeen/cython,acrispin/cython,mrGeen/cython,fperez/cython,bzzzz/cython,acrispin/cython,madjar/cython,larsmans/cython,JelleZijlstra/cython,larsmans/cython,ABcDexter/cython,larsmans/cython,achernet/cython,ABcDexter/cython,acrispin/cython,slonik-az/cython,achernet/cython,hickford/cython,fabianrost84/cython,scoder/cython,encukou/cython,dahebolangkuan/cython,ABcDexter/cython,mrGeen/cython,JelleZijlstra/cython,encukou/cython,da-woods/cython,ABcDexter/cython,hpfem/cython,acrispin/cython,scoder/cython,cython/cython,bzzzz/cython,roxyboy/cython,ChristopherHogan/cython,c-blake/cython,fperez/cython,hpfem/cython,encukou/cython,fperez/cython,c-blake/cython,roxyboy/cython,scoder/cython,dahebolangkuan/cython,marscher/cython,slonik-az/cython,madjar/cython,mcanthony/cython,andreasvc/cython,dahebolangkuan/cython,c-blake/cython,hpfem/cython,fabianrost84/cython,slonik-az/cython,roxyboy/cython,da-woods/cython,achernet/cython,ChristopherHogan/cython,rguillebert/CythonCTypesBackend,bzzzz/cython,JelleZijlstra/cython,achernet/cython,andreasvc/cython,andreasvc/cython,larsmans/cython,dahebolangkuan/cython,ChristopherHogan/cython,bzzzz/cython,da-woods/cython,andreasvc/cython,ABcDexter/cython,marscher/cython,madjar/cython,madjar/cython,fperez/cython,encukou/cython,hickford/cython,cython/cython,marscher/cython,encukou/cython,mcanthony/cython,mrGeen/cython,fabianrost84/cython,c-blake/cython,achernet/cython,mrGeen/cython,scoder/cython,hickford/cython,c-blake/cython,slonik-az/cython,fabianrost84/cython,hickford/cython,roxyboy/cython,roxyboy/cython,mcanthony/cython,acrispin/cython,hhsprings/cython,fabianrost84/cython,hhsprings/cython,andreasvc/cython,dahebolangkuan/cython,mcanthony/cython,fperez/cython,slonik-az/cython,hhsprings/cython,cython/cython,hhsprings/cython,marscher/cython,marscher/cython,rguillebert/CythonCTypesBackend,hhsprings/cython,rguillebert/CythonCTypesBackend