Blender exporter taking flipyz into account
Blender exporter normal bug fix

Global rotation is not taken into account for normals in loader.
This leads to all objects/cameras/lights in the scene being rotated correctly,
but with normals pointing into the wrong direction.

Not applying rotation at all fixes this problem
Add start and end events triggered on mouse/wheel/touch down/up for trackball control

The start and end events can be used to start or stop an animation loop, for example, so that the animation loop does not have to run continuously.
More verbose description for opacity/transparent
Merge branch 'dev' of https://github.com/mrdoob/three.js into dev
Merge branch 'dev' of https://github.com/mrdoob/three.js into dev
Link constants to the docs pages that list possible values
Link constants in MeshLambertMaterial to relevant docs pages
couple more files of linking constants to docs pages
Use hardware skinning where possible for Collada imports
Updated helper to properly track light.target
Editor: material.side wasn’t being saved. Fixes #4107.
Updated builds.
Merge branch 'dev-dlhelper' of https://github.com/WestLangley/three.js into dev
Merge branch 'blender-camera-flipyz-fix' of https://github.com/joostfaassen/three.js into dev
Merge branch 'dev' of https://github.com/Bjvanminnen/three.js into dev
Merge branch 'blender-normal-fix' of https://github.com/joostfaassen/three.js into dev
Merge branch 'startend' of https://github.com/jasongrout/three.js into dev
Merge branch 'HardwareSkinningCollada' of https://github.com/rchadwic/three.js into dev
Code clean up.