Update Postgresql.hs
Merge pull request #293 from nnovikov/maintain/1.3

Update Postgresql.hs
Version bump
set write concern of w=1 instead of j=1
use defaultAccessMode
mongoDB selectSource options and use Acquire

set the options snapshot=True and NoCursorTimeout
use Acquire to close the cursor
Merge remote-tracking branch 'origin/maintain/1.3'

Conflicts:
	persistent-mongoDB/persistent-mongoDB.cabal
	persistent-postgresql/persistent-postgresql.cabal
only set the $snapshot option when not sorting