Support spaces for tags that only ever contain a single text string value (i.e. material names, texture file names) in the OBJ converter.

Throw a decent error on missing font.

It throws an error when the font is missing.
Ex: "The font helvetiker with normal weight and normal style is missing.

Fixes #4923.

Now is possible to do:

    obj.add( obj2, obj3 );

As well as:

    obj.add( obj2 ).add( obj3 );

Fixes #4958.

Removed unused var verticesCount from OBJMTLLoader.js

Removed `var verticesCount` as per #4968.

Don't throw on empty glyph

add uuid to docs

Update ExtrudeGeometry.html

* remove the Shapebb property

New example WebGl-Geometry-Text-2 uses new triangulation PnlTri.js V1.0

Bower component: use minified version as the main file.

DigitalGlitch postprocessing effect

Update ShadowMapPlugin.html

Fixed links to WebGLRenderer

CanvasRenderer still needs some sort of masking...

That's the output firefox wants: https://air.mozilla.org/virtual-reality-the-future-of-the-web/