CLI implementation
Merge pull request #171 from tssajo/upstream

CLI implementation
Update README.md
Minify cleancss-browser.js.

See https://github.com/GoalSmashers/clean-css/pull/262/
Merge remote-tracking branch 'upstream/gh-pages' into gh-pages
Minor README.md change: installation instructions were there twice
Improvements and fixes in CLI and sample-cli-config-file.conf
Important change in package.json file to make CLI usable when html-minifier is installed via NPM