Send spec output to an editor pane rather than generic view.

* Uses Workspace#open() method to create an editor pane.
* Tried opening the pane in the "down" position, but it opened a new tab instead, so it's still opening at the "right" position.
* Also change out method call from possibly deprecated activePaneItem() to getActiveEditor()?
* Could stand to split out some code to separate method
* No tests!