make headNode local and remove visibility trick, that we don't need anymore
make headNode local and remove visibility trick, that we don't need anymore

Swaven/l20n.js,projectfluent/fluent.js,zbraniecki/l20n.js,stasm/l20n.js,Pike/l20n.js,l20n/l20n.js,zbraniecki/fluent.js,projectfluent/fluent.js,Pike/l20n.js,mail-apps/l20n.js,zbraniecki/fluent.js,mail-apps/l20n.js,projectfluent/fluent.js