add a backboneio middleware that generates an id from the timestamp on 'create' messages

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
make sure we're not overriding an id

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
make the _id middleware into it's own function

Signed-off-by: Tomas Neme <lacrymology@gmail.com>
avoid creating the moment() object if unnecessary

Signed-off-by: Tomas Neme <lacrymology@gmail.com>