Update WhatsNew.md with new features in 0.6.0
Update WhatsNew.md with new features in 0.6.0

lsegal/yard,jreinert/yard,thomthom/yard,amclain/yard,jreinert/yard,thomthom/yard,jreinert/yard,lsegal/yard,amclain/yard,iankronquist/yard,lsegal/yard,amclain/yard,alexdowad/yard,ohai/yard,thomthom/yard,herosky/yard,travis-repos/yard,alexdowad/yard,iankronquist/yard,alexdowad/yard,herosky/yard,iankronquist/yard,ohai/yard,travis-repos/yard,ohai/yard,herosky/yard