fix test by using 'signed char' instead of platform dependend 'char'
fix test by using 'signed char' instead of platform dependend 'char'

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