mishoo/UglifyJS2 — pull request #600 by KenPowers (2015-01-01 06:08:29+00:00)
Title: Use yargs instead of optimist.

[`optimist`](https://github.com/substack/node-optimist) has been deprecated. [`yargs`](https://github.com/chevex/yargs), which started as a fork of `optimist`, is now the official successor.