Call DataScript DB `conn` for Datomic parity?

[sgrove]

There isn't a separation between a connection and a DB in DataScript as there is in Datomic (will there be, with the webpeer?), but it might be nice to present the same interface on both platforms. Right now the DS DB inside (:db dato) is the atom, and can be deref'd for reading, or transacted into. I like the idea of having the atom in (:conn dato) and a separate (dato/db (:conn dato)) function for parity.