Fix add_to_builtins import for Django 1.7
Fix add_to_builtins import for Django 1.7

stephenmcd/mezzanine,jerivas/mezzanine,christianwgd/mezzanine,wbtuomela/mezzanine,adrian-the-git/mezzanine,nikolas/mezzanine,douglaskastle/mezzanine,batpad/mezzanine,dustinrb/mezzanine,ryneeverett/mezzanine,Skytorn86/mezzanine,emile2016/mezzanine,AlexHill/mezzanine,SoLoHiC/mezzanine,saintbird/mezzanine,viaregio/mezzanine,wbtuomela/mezzanine,AlexHill/mezzanine,wbtuomela/mezzanine,fusionbox/mezzanine,damnfine/mezzanine,jjz/mezzanine,dustinrb/mezzanine,dovydas/mezzanine,Kniyl/mezzanine,stephenmcd/mezzanine,webounty/mezzanine,sjdines/mezzanine,Kniyl/mezzanine,PegasusWang/mezzanine,webounty/mezzanine,frankchin/mezzanine,damnfine/mezzanine,mush42/mezzanine,sjdines/mezzanine,gradel/mezzanine,biomassives/mezzanine,jerivas/mezzanine,wyzex/mezzanine,theclanks/mezzanine,geodesign/mezzanine,dsanders11/mezzanine,wyzex/mezzanine,ryneeverett/mezzanine,saintbird/mezzanine,mush42/mezzanine,webounty/mezzanine,gradel/mezzanine,sjuxax/mezzanine,christianwgd/mezzanine,damnfine/mezzanine,agepoly/mezzanine,readevalprint/mezzanine,christianwgd/mezzanine,promil23/mezzanine,industrydive/mezzanine,ZeroXn/mezzanine,ZeroXn/mezzanine,Cicero-Zhao/mezzanine,spookylukey/mezzanine,joshcartme/mezzanine,promil23/mezzanine,mush42/mezzanine,dsanders11/mezzanine,biomassives/mezzanine,tuxinhang1989/mezzanine,jerivas/mezzanine,viaregio/mezzanine,Skytorn86/mezzanine,adrian-the-git/mezzanine,douglaskastle/mezzanine,promil23/mezzanine,spookylukey/mezzanine,frankchin/mezzanine,molokov/mezzanine,industrydive/mezzanine,dsanders11/mezzanine,SoLoHiC/mezzanine,emile2016/mezzanine,joshcartme/mezzanine,theclanks/mezzanine,Cajoline/mezzanine,dekomote/mezzanine-modeltranslation-backport,sjuxax/mezzanine,Cajoline/mezzanine,frankchin/mezzanine,douglaskastle/mezzanine,dekomote/mezzanine-modeltranslation-backport,readevalprint/mezzanine,dovydas/mezzanine,joshcartme/mezzanine,eino-makitalo/mezzanine,PegasusWang/mezzanine,jjz/mezzanine,nikolas/mezzanine,nikolas/mezzanine,batpad/mezzanine,frankier/mezzanine,jjz/mezzanine,readevalprint/mezzanine,viaregio/mezzanine,frankier/mezzanine,eino-makitalo/mezzanine,emile2016/mezzanine,tuxinhang1989/mezzanine,theclanks/mezzanine,spookylukey/mezzanine,saintbird/mezzanine,molokov/mezzanine,sjuxax/mezzanine,vladir/mezzanine,molokov/mezzanine,Cajoline/mezzanine,PegasusWang/mezzanine,eino-makitalo/mezzanine,adrian-the-git/mezzanine,wyzex/mezzanine,tuxinhang1989/mezzanine,geodesign/mezzanine,agepoly/mezzanine,dekomote/mezzanine-modeltranslation-backport,cccs-web/mezzanine,cccs-web/mezzanine,vladir/mezzanine,vladir/mezzanine,Cicero-Zhao/mezzanine,agepoly/mezzanine,biomassives/mezzanine,frankier/mezzanine,SoLoHiC/mezzanine,ZeroXn/mezzanine,dustinrb/mezzanine,industrydive/mezzanine,Kniyl/mezzanine,geodesign/mezzanine,dovydas/mezzanine,Skytorn86/mezzanine,ryneeverett/mezzanine,stephenmcd/mezzanine,sjdines/mezzanine,fusionbox/mezzanine,gradel/mezzanine