Added support for file_extension for file drivers.
Added support for file_extension for file drivers.

Bilge/DoctrineModule,marek1989/DoctrineModule,UFOMelkor/DoctrineModule,alirezarahmani/DoctrineModule,netiul/DoctrineModule,doctrine/DoctrineModule,malukenho/DoctrineModule,gencer/DoctrineModule,vasildakov/DoctrineModule,mpalourdio/DoctrineModule,malukenho/DoctrineModule,UFOMelkor/DoctrineModule,inbaz/DoctrineModule,Bilge/DoctrineModule