Customizer: switch to UglifyJS2 (v2.4.13).

The uglify build is generated with `uglifyjs --self -o uglify.min.js`.
Add the jquery check in customizer's output.
Add the license header in the non minified build too.
Run `grunt`.
fixes #11099 - $.collapse() overrides the original dimension of the coll...
fixes #13296 Dropdown disappears with right-click on Firefox
Merge pull request #13354 from twbs/fat-13296

fixes #13296 Dropdown disappears with right-click on Firefox
Merge pull request #13306 from twbs/fat-11099

fixes #11099 - $.collapse() overrides the original dimension of the coll...
Update composer.json

Update minor version of alias to proper.
Merge pull request #13385 from vnagara/patch-1

Update composer.json
move call for removeBackdrop() to backdrop()

Closes #11958 by rebasing & merging it
Merge pull request #13151 from twbs/customizer-uglifyjs2

Customizer: switch to UglifyJS2
Tweak JS style and the relevant JSHint and JSCS checks.
Comply to the new style.
Remove `laxbreak`.
Remove `boss`.
Enable `requireCurlyBraces`.
Enable `es3`.
Switch to using plain `if/else` statements when there's no assignment.

The minizer outputs the same code anyway, and this has better readability.

Conflicts:
	js/modal.js
Minor whitespace changes.