mishoo/UglifyJS2 — pull request #48 by w00kie (2012-11-14 01:54:33+00:00)
Title: make source-map-root and prefix act on sourceMappingURL, fixes #47

I've prepended the source-map-root to sourceMappingURL and made the prefix parameter remove levels from the filepath.
Since the prefix code is now used in two different places, I've made it into a function.