Will hopefully revert this reversion and land a fully-working version of UMD in v3.3.0.

Revert "some changes from #13801 - add strict mode back and =="
This reverts commit 2b302f69.

Revert "Fix regression of #10038 introduced by #13772"
This reverts commit e9d6756a.

Revert "MD/CommonJS/Globals #12909"
This reverts commit 1c6fa901.

Revert "address #13811"
This reverts commit f347d7d9.

Conflicts:
    js/carousel.js
    js/collapse.js
    js/dropdown.js
    js/modal.js
    js/tab.js
    js/tooltip.js