Modified to extend node-core

New release v0.4.1 -> Scala.js v0.6.20

Miscellaneous updates and fixes

Updated to v0.4.0

Upgraded to Scalajs.io v0.4.0-pre5

Test fixes

Removed deprecated methods

Pre-release updates

Miscellaneous fixes

1. Fixed issue with ErrorEvent - message was missing
2. Added missing API methods to various Phaser classes

Additional test class clean-up

Phaser fixes