Spina views should mostly override either onInitialRender() or onRender()

instead of render() because the latter manages important things like

model event registration and triggering render signals. This updates our

AbstractCommentBlockView to override the onInitialRender() method

instead of render(), which allows model event handlers to properly

register.
This fixes two regressions that we had:

1. When resizing/moving comments, the selection box wouldn't immediately

   update to the new size.

3. When created a new comment on top of an existing published one, the

   comment block view would only show the published one.

Ran unit tests.
Tested creating, deleting, moving and resizing region comments.
Tested adding a comment on top of an existing one.