add tests for 'raise ... from None'
add tests for 'raise ... from None'

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