fix three missed conversions to closures.  switch to extending math prototypes rather than replacing them.  This is to ensure that types created in closures within a type's prototype definition get their prototype updated with the full definition.

Renamed Vector3 projectPoint() to applyProjection() as per @WestLangley suggestion in bb873d16.

@WestLangley I've changed most of the vector.applyMatrix4() to vector.projectPoint().
Feel free to change back the ones that aren't needed (or let me know which ones can need to be changed back and I will do it).

Removed Vector* add() to addVectors() and addSelf() to add(). Same with sub, cross, min, max, lerp... Renamed Matrix* and Quaternion multiply() to multiplyMatrices(), multiplyQuaternions() and multiplySelf() to multiply(). See #2860.
Good thing we have a ton of examples to make sure nothing is broken. The unit tests also helped. However, I suspect I've left something unchanged.

Renamed .multiplyMatrix* to .applyMatrix* and .multiplyQuaternion to .applyQuaternion as suggested by @WestLangley in #2860.

Makes the code so much nicer imho...

use switch statements in Vector2/3/4.getComponents()/setComponents() based on it being 5-10x faster than index-to-name based on benchmark_vector3components.html

inline Vector2/3/4/Quaternion.length()/lengthSq() and optimize Vector2/3/4.setLength() with unit test coverage.

fixed #2728, Moved geometry primitives out of src/core into src/math.  src/core is now exclusive scene primitives.

More garbage collection friendly Box2.distanceToPoint(), Box3.distanceToPoint() and Vector3.distanceToSquared()

Would be great if the function to get angle to anonther vector could be implemented in this Vector3 class.
Hope you guys like the idea.