CoffeeScript debugging support

[paulvi]

Support for debugging of CoffeeScript.
For example, when setting breakpoint in .coffee file, it synchronizes with .chromium/._js breakpoint.

This requires library for reading coffee-generated SourceMaps.

[paulvi]

Introduction to JavaScript Source Maps
http://www.html5rocks.com/en/tutorials/developertools/sourcemaps/

[paulvi]

A large collection of declaration files for popular JavaScript libraries
https://github.com/borisyankov/DefinitelyTyped

e.g. Node
https://github.com/borisyankov/DefinitelyTyped/blob/master/node/node.d.ts