Included changes from branch by @crobi, which correctly exported the rotation for bones. His old branch was made before the newest exporter which supported multiple animations. This exporter merges the two branches together.
Found one more spot from existing exporter that needed to be merged into new exporter.
addressed changes per discussion with @mrdoob, @crobi on pull request: https://github.com/mrdoob/three.js/pull/4693/files#r11759573
Merge pull request #4693 from phfatmonkey/Exporter-AddQuatRotation

Exporter add quat rotation