webapp/help: adding metrics page and small reorga
webapp/help: adding metrics page and small reorga

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