v3.1.0

Update uglify-js to v3.1.0.

v3.0.1

v3.0.1.

v3.0.0

v3.0.0.

v2.3.0

v2.3.0.

v2.2.1

v2.2.1.

v2.2.0: Merge pull request #453 from gruntjs/update-uglify

Update uglify

v2.1.0

2.1.0.

v2.0.0: Update uglify to v2.7.0. (#416)

* bump uglify-js to 2.7

* Update files for `screw_ie8` being true in uglify 2.7.0.

* Minor lint tweaks.

* v2.0.0.

v1.0.2

v1.0.2. (#423) r=vladikoff