Corrected description of the "//" operator
Corrected description of the "//" operator

The operator was previously described to truncate the the value when it in fact floors the result of the division (which can be seen in https://github.com/fabpot/Twig/blob/master/lib/Twig/Node/Expression/Binary/FloorDiv.php#L20).
By the old description one would think that ``{{ -20 // 7 }}`` would yield -2 (as in ``(int)(-20/7)``) when it actually returns -3 (as in ``floor(-20/7)``). Floor is not truncate (cast to int).
robregonm/Twig,hhamon/Twig,twigphp/Twig,Tobion/Twig,dkarvounaris/Twig,fsw/Twig,nicolas-grekas/Twig,fsw/Twig,moufmouf/Twig,gamernetwork/Twig,nicolas-grekas/Twig,gencer/Twig,apishka/templater,moltin/Twig,bocharsky-bw/Twig,twigphp/Twig,bocharsky-bw/Twig,huang53798584/Twig,twigphp/Twig,znerol/Twig,loi-chuanoi/Twig,robregonm/Twig,bocharsky-bw/Twig,framewr/Twig,apishka/templater,derickr/Twig,dkarvounaris/Twig,framewr/Twig,phansys/Twig,fsw/Twig,craue/Twig,gamernetwork/Twig,moltin/Twig,gamernetwork/Twig,jamessingizi/Twig,iKwinto/Twig,craue/Twig,framewr/Twig,Rvanlaak/Twig,jamessingizi/Twig,hason/Twig,moufmouf/Twig,Tobion/Twig,Rvanlaak/Twig,znerol/Twig,hason/Twig,nicolas-grekas/Twig,hason/Twig,iKwinto/Twig,hhamon/Twig,derickr/Twig,gencer/Twig,phansys/Twig,iKwinto/Twig,Rvanlaak/Twig,dkarvounaris/Twig,robregonm/Twig,derickr/Twig,nicolas-grekas/Twig,hhamon/Twig,huang53798584/Twig,moufmouf/Twig,nicolas-grekas/Twig,Tobion/Twig,znerol/Twig,jamessingizi/Twig,huang53798584/Twig,moltin/Twig