Fix unit test failure from pull request #4878.  Added unit test for hiding Active Line highlight when editor has selection.

Here's the fix for the unit test errors caused by pull request #4878.  I moved the check out of the toggle command code and into the _setEditorOption() code per the suggestion of @jasonsanjose.

I also added a new unit test to check for the temporary hiding of the Active Line Highlight when there is an editor selection.  Tested the positive and negative scenarios.  Ran the entire test suite.  Everything looks good.  There are still quite a few errors in the unit test suite right now, but none appear to be related to my changes.