Merge pull request #130 from bartvanandel/patch-1

Fix Frobenius norm for mat4
fix 4th component in vec4.transformQuat output
fixes JSDoc formatting in gl-matrix
fixes JSDoc formatting in vec3
Adds an externs.js

These were kind of a pain to generate, so I thought you might want to provide them.  I kept a single copyright preamble in place, and put this in the root directory, let me know if you want me to change either of those.
Oops, wrong branch :(
Merge pull request #131 from acerix/master

fix 4th component in vec4.transformQuat output
Merge pull request #132 from nickgeorge/master

Fixes small JSDoc formatting errors in src/vec3 (and correspondingly dist/)
Fixed #129
Added VR-oriented mat4.perspectiveFromFieldOfView

Generates a perspective matrix give a VRFieldOfView object from the
(still experimental) WebVR API.