mrdoob/three.js — pull request #3020 by bhouston (2013-02-02 18:11:36+00:00)
Title: add Vector3.project, Vector3.ortho and Vector3.reflect

Based on the request here #3009 for a Vector3.reflect function, I have added 3 related functions:

```Vector3.project( normal )```, projects the current vector onto the normal based on the theory outlined here: http://en.wikipedia.org/wiki/Vector_projection

```Vector3.ortho( normal )```, similar to the above but returns the vector - the projection, the orthogonal component of the original value to the normal (the component of the vector that is projected onto the plane rather than on to the plane's normal). See here: http://www.euclideanspace.com/maths/geometry/elements/plane/lineOnPlane/index.htm

Note: ( project + ortho ) always equals the original vector value.

```Vector3.reflect( normal )``` reflects the current vector given the current implied plane normal. It utilises ortho() above.

Wrote 11 unit tests and they all pass.