Made MenusField also support dynamic changes to PAGE_MENU_TEMPLATES.
Made MenusField also support dynamic changes to PAGE_MENU_TEMPLATES.

This costs a call to a private Field._get_choices(), because
Field.choices is already a property.

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