2.3 - Added db.store() for localstorage, added delay to db().callback…

…(), added onChange

- db.store("name") will store the DB in local storage under the provided
name - changes are auto synced - db().callback(fun,delay) is now
possible like setTImeout (which it uses). Delay is 0 by default -
settings({onChange:fun}) has been added, the whole collection is passed
into onChange within a setTImeout when a change is made to the DB