Use uglify@2.4.16

I'm hoping you'll consider publishing a release with Uglify 2.4.16.  There are a [number of fixes](https://github.com/mishoo/UglifyJS2/compare/v2.4.15...v2.4.16) in this release.  I'm looking for this one in particular: https://github.com/mishoo/UglifyJS2/commit/62bda71c853e844f0477873397ae7ae211bc7dc8.