don't allow views from another window to be next/previouskeyViews
Merge pull request #1837 from BlairDuncan/keyViewLoopInfinateLoopFix

Fixed: views from other windows cannot be next/previous key views

Previously, a view from another window could be set as the next/previous key view, which would result in unexpected behavior, including an infinite loop.

This commit ensures the proposed next/previous view belongs to the same window as the view to which it will be chained.