Double render fix

Reducing the calls to the view creation to either call `render` on the client side or `attach` on the hydration step.  This should save some lifting in the view helper as it only needs to pass through a div with the data needed for the view, rather than creating an instance of the view and destroying it.

This also fixes a memory leak in the `initialization` step in the handlebars helper where it was setting all of the `listenTo` scope incorrectly (now they're not even being called).

This will _not_ be a breaking change from `rendr-handlebars` and will continue to function the same way if that package isn't updated.
`attachOrRender` has signature of `(element, parentView)` and it sets parentView there. 
That will actually set it to `undefined`, if you aren't passing it here.