Added the core of a session handler that uses stash as it's backend.
Added the core of a session handler that uses stash as it's backend.

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