From SocialCalc to EtherCalc

This project exemplifies better than all others the advantage of being able to run the same language on the front and the backend. And it is awesome as well! Kudos.

This is a draft for an upcoming book, and comments/feedback would be much appreciated!

BTW, for environments where WebWorker-Threads is not an option (e.g. Node.js 0.6), https://github.com/audreyt/ethercalc/commit/0f41d20324833885... provides a backward-compatible fallback.