* updated webglrenderer docs to reference GLState constants

* Improved doc / Contants / GLState

pedant mode on.

camera, core and math  dirs + a stray "]" in WebGLRenderer docs

* Legacy: Moved EventDispatcher.prototype.apply.

* WebGLShadowMap: Renamed face selection parameters.

* WebGLShadowMap: Clarified code.

* WebGLShadowMap: Renamed face selection parameters.

* Removed useless and outdated ShadowMapPlugin docs.

* Consistified WebGLState, added culling.

* Let WebGLShadowMap set culling through WebGLState.

* WebGLShadowMap: Removed redundant state setup.

* WebGLRenderer: Removed needless factorization.

* Removed cull state mess from WebGLShadowMap.

- Instead flip .side on the depth material with the same effect.
- See #8760.

* Updated builds.

* Improved precision of RGBA fixpoint packing.

* Added switch to enable double-sided shadow casters.

- Off by default, see #8692

* Updated WebGLRenderer docs, shadow mapping.

* Enabled back face shadows, webgl_clipping_advanced.

* Implemented user-defined clipping planes.

* Renderer: Minor documentation update.

* Implements object-level clipping.

* Renderer: Minor cosmetic changes.

* Fixed lethal typo in normal shader.

* Let shadows respect .side of object's material.

* Fixed Plane.applyMatrix4.

- Scale denormalized but did not scale the position
- Projection is not supported (solved by documentation)
- Removed unnecessary copying to make up for the normalization
- Still arguably too heavy

* Added custom clipping example.

* Clipping: Fixed transition to disabled state.

* Improved custom clipping example.

- GUI dependency of volume visualization on Enabled state
- Larger radius for cylindrical global clipping area

* No .matrixAutoUpdate = false in clipping example.

* Let ShadowMap check renderer.localClippingEnabled.

* Added a simplified clipping example.

Discovered while investigating #7680

Remove `.autoUpdateObjects` property and clean-up constructor parameter
list.

Renderer no longer take window.devicePixelRatio by default. Added .getPixelRatio() and .setPixelRatio(). See #5627.

WebGLRenderer's documentation incorrectly stated that if no parameters were passed to it, the 'clear' method will not clear any buffers. The default behaviour is in fact the opposite: if an argument is undefined, the corresponding buffer will be cleared. The document now correctly describes the default behaviour.
Source code of the method: https://github.com/mrdoob/three.js/blob/master/src/renderers/WebGLRenderer.js#L368

line256 If forceClear is true(,) the depth,

autoScaleCubemaps
Default is true. If set, then Cubemaps are scaled, when the(y) are bigger the(than) the maximum size, to make sure that they aren't bigger then(than) the maximum size.