fix string constants defined in extension classes
fix string constants defined in extension classes

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