ref

fix exports on Node.js
Date::format: use ~ ISO8601 format
Date.addLocale: use Sugar.js format
remove Deferred::clone
Symbol.iterator: '@@iterator' -> Symbol('Symbol.iterator'). Sorry, FF.
Object.make: remove desc argument
src/init.js -> src/core.js
src/iterator.js -> src/iterators.js
src/es6c.js -> src/collections.js