Move remaining Makefile tasks into the Jakefile.
Update Elsewhere links to new GitHub locations.
Switch to Pure from YUI CSS. Add Yahoo logo.
Fix light sub-heading on landing page.

The correct weight was not being pulled in. Only Safari tried rendering
at the weight of 100. A heavier 300 looks better and across browsers.

Remove unused Prettify CSS from the landing page.
Only strip 2 lines from the Contribute page.
Update contribute doc with new URLs, branding.
Update browser versions on landing page.