add THREE.error/THREE.warning to allow for easy redirection of THREE.js specific errors and warnings.

Moved Projector's .projectVector and .unprojectVector to Vector3 .projectCamera and .unprojectCamera.

Removed another unneeded quaternion variable. As per @WestLangley suggestion in 0e9f32f1.

added notices that Vector3.setEulerFromRotationMatrix/setEulerFromQuaternion have been removed.  Not deprecating because the target class has changed, it isn't just a function rename.

Misteriously when using the latest version of the lib on the project I'm working on I'm getting this error:
> Uncaught TypeError: Object [object Object] has no method 'set'
This is caused when THREE.UniformsLib.common.diffuse initialises a THREE.Color (THREE.Color.set() seems to be undefined then).
For some reason this only happens when I load Box2D before three.js. If I load it after is all good. But this fixes the problem too.
/ping @bhouston

Improved implementation and unit test for Vector3.angleTo to account for numerical problems outside of full [-1,1] range.

Fixed bug in Vector3.angleTo where NaN was being returned instead of zero. Added corresponding unit test.