Close document in content perspective when starting to VE-edit it

In order to provide a sane and consistent integration between editing a document in the content perspective and editing it in the channel manager (visual editing), whenever we "start editing" a document in the channel manager, if that document is also open in an editor in the content perspective (view or edit mode), that editor should be killed without invoking any workflow operation on the corresponding document (and without saving changes in the JCR session*).

By "start editing", we mean that we successfully created the draft in Visual Editing. This can happen
1) when opening the right side panel
2) when clicking an edit content button of a different document while the right side panel is already open

• any pending changes would already haven been saved upon leaving the editor focus (switching to other tab/perspective)