Extending #458 'open in new window' feature with optional Shift modifier. Shift + click in resource tree to edit in new window for users with no middle mouse button (e.g. Apple magic mouse, trackpads, etc)
Added shift modifier to tree click, that will open resource in a new window

* origin/pr/819:
  Extending #458 'open in new window' feature with optional Shift modifier. Shift + click in resource tree to edit in new window for users with no middle mouse button (e.g. Apple magic mouse, trackpads, etc)