Rename Matrix*.multiplyVector3Array() to Matrix*.applyToVector3Array()

... so as to remain consistent with our naming conventions.

Also, `Matrix4.multiplyVector3Array()` was calling `Vector3.applyProjection()`, instead of `Vector3.applyMatrix4()`.

If we want to have the ability to apply a projection matrix to elements of an array, we should create an additional method: `Matrix4.applyProjectionToVector3Array()`. Currently, that capability is not needed.