Updated the memcache handler to call isAvailable() on the sub handlers.
Updated the memcache handler to call isAvailable() on the sub handlers.

alawnchen/Stash,theUniC/Stash,alawnchen/Stash,tedious/Stash,csburton/Stash,AndrewCarterUK/Stash,andrerom/Stash,andrerom/Stash,AndrewCarterUK/Stash,bankiru/Stash,csburton/Stash,theUniC/Stash,graphis/Stash,tedious/Stash,graphis/Stash,bankiru/Stash,localheinz/Stash,localheinz/Stash,jaredtking/Stash,jaredtking/Stash