Allow builtin filters to be defined in modules directly unter django_assets.filter, rather than requiring a subdirectory.
Allow builtin filters to be defined in modules directly unter
django_assets.filter, rather than requiring a subdirectory.

heynemann/webassets,JDeuce/webassets,aconrad/webassets,john2x/webassets,0x1997/webassets,wijerasa/webassets,florianjacob/webassets,aconrad/webassets,scorphus/webassets,aconrad/webassets,scorphus/webassets,heynemann/webassets,glorpen/webassets,glorpen/webassets,john2x/webassets,glorpen/webassets,wijerasa/webassets,rs/webassets,florianjacob/webassets,heynemann/webassets,JDeuce/webassets,0x1997/webassets