fixed tooltips, added separate gemDiv

d3functions.js:
--added error handling if no legendary gems were used

renderMethods.js:
--caches results

hero.css:
--tooltip now properly shows header

leaderboard.css:
--set width+height for divs to be % instead of px

classleaderboard.ejs:
--added gemGraphDiv

hero.ejs:
--added links for active/passive skills
--tootips now show for skills