Fixed CPString's commonPrefixWithString to be faster.
Fixed CPString's commonPrefixWithString to be faster.

rgv151/cappuccino,mrcarlberg/cappuccino,wangshijin/cappuccino,rgv151/cappuccino,daboe01/cappuccino,mrcarlberg/cappuccino,280north/cappuccino,280north/cappuccino,krodelin/cappuccino,tancred/cappuccino,cacaodev/cappuccino,rgv151/cappuccino,wangshijin/cappuccino,deltaprojects/cappuccino,daboe01/cappuccino,cacaodev/cappuccino,daboe01/cappuccino,280north/cappuccino,krodelin/cappuccino,enquora/cappuccino,FrankReh/cappuccino,dgvivero/CappCoreData,daboe01/cappuccino,zittix/cappuccino,daboe01/cappuccino,Dogild/cappuccino,enquora/cappuccino,cacaodev/cappuccino,cappuccino/cappuccino,eventualbuddha/cappuccino,primalmotion/cappuccino,akshell/cappuccino,FrankReh/cappuccino,280north/cappuccino,Dogild/cappuccino,Dogild/cappuccino,dgvivero/CappCoreData,cappuccino/cappuccino,dgvivero/CappCoreData,AlexanderMazaletskiy/cappuccino,deltaprojects/cappuccino,Rosch/cappuccino,krodelin/cappuccino,AlexanderMazaletskiy/cappuccino,zittix/cappuccino,dgvivero/CappCoreData,zittix/cappuccino,cappuccino/cappuccino,mrcarlberg/cappuccino,zittix/cappuccino,tancred/cappuccino,rgv151/cappuccino,kidaa/cappuccino,280north/cappuccino,akshell/cappuccino,eventualbuddha/cappuccino,AlexanderMazaletskiy/cappuccino,rgv151/cappuccino,FrankReh/cappuccino,tolmasky/cappuccino,tancred/cappuccino,Dogild/cappuccino,primalmotion/cappuccino,tolmasky/cappuccino,deltaprojects/cappuccino,krodelin/cappuccino,koamac/Cappuccino,koamac/Cappuccino,FrankReh/cappuccino,primalmotion/cappuccino,eventualbuddha/cappuccino,krodelin/cappuccino,tancred/cappuccino,Rosch/cappuccino,kidaa/cappuccino,mrcarlberg/cappuccino,rgv151/cappuccino,daboe01/cappuccino,Rosch/cappuccino,koamac/Cappuccino,zittix/cappuccino,FrankReh/cappuccino,cappuccino/cappuccino,mrcarlberg/cappuccino,wangshijin/cappuccino,cappuccino/cappuccino,krodelin/cappuccino,mrcarlberg/cappuccino,cacaodev/cappuccino,AlexanderMazaletskiy/cappuccino,deltaprojects/cappuccino,kidaa/cappuccino,cacaodev/cappuccino,Dogild/cappuccino,dgvivero/CappCoreData,enquora/cappuccino,wangshijin/cappuccino,cacaodev/cappuccino,enquora/cappuccino,cappuccino/cappuccino,Dogild/cappuccino,primalmotion/cappuccino,tancred/cappuccino,eventualbuddha/cappuccino,Rosch/cappuccino,tolmasky/cappuccino,zittix/cappuccino,Rosch/cappuccino,primalmotion/cappuccino,FrankReh/cappuccino,FrankReh/cappuccino,kidaa/cappuccino,tolmasky/cappuccino,AlexanderMazaletskiy/cappuccino,daboe01/cappuccino,enquora/cappuccino,enquora/cappuccino,deltaprojects/cappuccino,cappuccino/cappuccino,cacaodev/cappuccino,Rosch/cappuccino,kidaa/cappuccino,krodelin/cappuccino,akshell/cappuccino,tancred/cappuccino,enquora/cappuccino,rgv151/cappuccino,deltaprojects/cappuccino,kidaa/cappuccino,koamac/Cappuccino,wangshijin/cappuccino,tolmasky/cappuccino,primalmotion/cappuccino,AlexanderMazaletskiy/cappuccino,mrcarlberg/cappuccino,zittix/cappuccino,primalmotion/cappuccino,Dogild/cappuccino,mrcarlberg/cappuccino,FrankReh/cappuccino,wangshijin/cappuccino,deltaprojects/cappuccino,koamac/Cappuccino,Rosch/cappuccino,akshell/cappuccino,koamac/Cappuccino