Add deprecation warning for global CodeMirror the first time it's called from a given location
Don't get stack if oncePerCaller isn't set
Merge from master
Merge pull request #7190 from adobe/nj/deprecate-global-cm

Add deprecation warning for global CodeMirror the first time it's called from a given location
Update CodeMirror to v4 RC2
Restore original selection behavior and fix up unit tests for CM change to primary selection default
Merge pull request #7214 from adobe/nj/fix-unit-tests

Restore original selection behavior and fix up unit tests for recent CM change