bug 1011486: b2g balrog submission should point at dated dirs, not latest-* - fallback to even older style mar urls as a bustage fix. r=aki

--HG--
branch : production
extra : transplant_source : %8A-%F2%E0m%B4%CA%A3%F3%F2%F2Fy%F4%89%AED%FB%C2%D0