Change 'outstanding' to 'noteworthy' in the README

Based on commit scala-js/scala-js-website@794da5b76b444 which fixed
issue scala-js/scala-js-website#8.
Merge pull request #137 from jonas/readme-noteworthy-features

Change 'outstanding' to 'noteworthy' in the README
Fix #158: Implement java.util.Random.nextLong()