Added documentation to the Session class.
Added documentation to the Session class.

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