BREAKING CHANGE: Refactored to use Promises

This main release contains big refactoring to "es6 age". All API's are now Promise based and data receiving is now more robust - less "command timeout" :). There is also included several new groups and commands that was missing and there is now all available commands as a Promise functions so no need to use anymore sendCommand(..)- instead propose to use new API's directly (e.g. onkyo.powerOn()).

Changes

#3 refactored for es6 age