Fix #14180. Allow cross-frame use of focusin/out. Close gh-1369.
Revert "Fix #14180. Allow cross-frame use of focusin/out. Close gh-1369."

This reverts commit 9b6f0745805941a6d7b7c16c02cf56ab00021c82.
Add tests for class manipulation on jQuery object containing more than one element. Close gh-1404.