Added missing @throws in Twig_LoaderInterface
Added missing @throws in Twig_LoaderInterface

Based on Twig_Loader_Chain implementation, this seems to be the possible exceptions that can be thrown by loaders.
znerol/Twig,bocharsky-bw/Twig,maartendekeizer/Twig,gamernetwork/Twig,nicolas-grekas/Twig,gencer/Twig,bocharsky-bw/Twig,framewr/Twig,Rvanlaak/Twig,robregonm/Twig,hhamon/Twig,jamessingizi/Twig,craue/Twig,twigphp/Twig,dkarvounaris/Twig,nicolas-grekas/Twig,moufmouf/Twig,apishka/templater,znerol/Twig,iKwinto/Twig,gamernetwork/Twig,framewr/Twig,hhamon/Twig,robregonm/Twig,iKwinto/Twig,twigphp/Twig,Rvanlaak/Twig,markstory/Twig,phansys/Twig,nicolas-grekas/Twig,derickr/Twig,markstory/Twig,moltin/Twig,fsw/Twig,fsw/Twig,hason/Twig,Tobion/Twig,apishka/templater,iKwinto/Twig,moufmouf/Twig,bocharsky-bw/Twig,hason/Twig,moufmouf/Twig,craue/Twig,framewr/Twig,robregonm/Twig,nicolas-grekas/Twig,dkarvounaris/Twig,Rvanlaak/Twig,huang53798584/Twig,hhamon/Twig,gamernetwork/Twig,derickr/Twig,dkarvounaris/Twig,derickr/Twig,twigphp/Twig,moltin/Twig,hason/Twig,peterkokot/Twig,jamessingizi/Twig,sstok/Twig,huang53798584/Twig,sstok/Twig,Tobion/Twig,fsw/Twig,moltin/Twig,Tobion/Twig,peterkokot/Twig,nicolas-grekas/Twig,loi-chuanoi/Twig,huang53798584/Twig,gencer/Twig,maartendekeizer/Twig,znerol/Twig,phansys/Twig,jamessingizi/Twig