Rolling back engine version.
Adding readability.
Updating engine version range.
Giving up on post install / pre publish scripts for compiling coffee to
js during the install. This proved to have many problems, some coming
from NPM, some related to cross-platform issues and so on.

So from now one the package will be delivered as pure js version, and
also versioned (check gitignore) into git so users using it as a
git-dependency will also receive the same output.
Releasing 0.3.13