fix mixin definitions inside other mixin definitions
fix mixin definitions inside other mixin definitions

mapbox/carto,madeinqc/carto,whitelynx/carto,CartoDB/carto,1ec5/carto,midnightcomm/carto,clhenrick/carto,CartoDB/carto,gravitystorm/carto,pnorman/carto,stefanklug/carto,tomhughes/carto