webapp/iframe comm: some cleanup
webapp/iframe comm: some cleanup

DrXyzzy/smc,sagemathinc/smc,sagemathinc/smc,tscholl2/smc,tscholl2/smc,DrXyzzy/smc,tscholl2/smc,DrXyzzy/smc,DrXyzzy/smc,tscholl2/smc,sagemathinc/smc,sagemathinc/smc,tscholl2/smc