Allows up to 4 bone influences per mesh vertex

Added an option to allow a user to specify up to 4 (min of 1, default of 2) bone influences per vertex.
https://github.com/mrdoob/three.js/issues/5545

Additional changes:
- Updated the bone mapping logic to instead record the maps locally within the parsing method and not store to the Geometry() instance
- Added package modules missing from import
- Cleanup of unused imports and variables
- Updated review.js to support the camera tests.