- Also linearize memory access in set.

Note: Allows in-place inversion, e.g. `m.getInverse( m )`.

The previous flag is incorrectly named. The flag is supposed to signify a
degenerate matrix. Fixes issue #7612.

- Better inheriting of `clone` + `copy` methods where appropriate. This is done by calling `new this.constructor()` in parent classes. `this.constructor` refers to the current instance's constructor, so it should all compose nicely;

- Pass in attributes directly as arguments to constructor when cloning, where appropriate (if arguments pattern is different from parent class). This mean `copy` isn't relied on to set those attributes.

- Change order of `clone` in some files (for better visibility into its relationship with `copy`, and to maintain consistency; can return to previous order if necessary);

- Fix CubeTexture's clone method

Changed some examples to use SphereBufferGeometry
Added coord getters to Buffers
Changed Matrix apply to work with both Interleaved and Regular Buffers

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

Implemented Geometry2.merge().
Added offset and length parameters to Matrix3/Matrix4.applyToVector3Array().

As far as I'm aware this is no longer needed.

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

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.

@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).

Makes the code so much nicer imho...