SQL no longer is piped into psql, but sent over the DB connection in-process
SQL no longer is piped into psql, but sent over the DB connection in-process

This additionally changes migrations to work in a single transaction which can
be rolled back if anything fails. upgradedb --execute is atomic.

iivvoo/nashvegas,GunioRobot/nashvegas,binarydud/nashvegas,jpic/nashvegas,marcinn/nashvegas,jpic/nashvegas,dstufft/nashvegas,peterbe/nashvegas,GunioRobot/nashvegas,dstufft/nashvegas,jonathanchu/nashvegas,paltman-archive/nashvegas,coffindragger/nashvegas,peterbe/nashvegas,coffindragger/nashvegas,dcramer/nashvegas,paltman/nashvegas