Reorder selections section
Break into Essential and extended
De-public a couple unused methods
Nothing uses this function, not internal nor packages.
De public a non-used method
Add Editor::setSelectedScreenRanges()
Deprecate getSelection
Deprecate getCursor()
Remove getSelectionAtIndex

We’re going to eventually get rid of the clone in 
getSelections / getCursors freeze those properties 
and return them directly. Then they can operate 
on the list garbage free.