* Water grid simulation w/ ShaderMaterial cloned from MeshPhongMaterial

* Water shader works with texture heightmap

* Added GPUComputationRenderer, I'm about to test it

* GPUComputationRenderer works with water simulation

* Interaction with mouse

* Added water viscosity, simple geometry for mouse picking

* Put pass thru shaders in GPUComputationRenderer. Some minor refactoring.

* Code revisison, added comments and explanations. Inverted mouse Y coord.

* Added GUI controls for some water parameters.

* Commencing conversion of birds gpu demo to GPUComputationRenderer

* Converted gpu birds demo to GPUComputationRenderer and fixed bugs in it.

* Solved mouse bug.

* Optimized smoothWater(), renamed some GPUComputationRenderer methods.

* Substituted old bird gpu implementation. Preparing for new demo.

* Removing old SimulationRenderer

* GPU protoplanets demo started. Minor tweaks in the other demos

* Starting to implement the particle demo

* $th component of texture now is usable. It was the GPUComputationRenderer
pass-through fragment shader.
Next thing to do is use a texture that contains (vx, vy, vz, mass).

* Particles already move. Next is gravity interaction.

* Gravity interaction done. Next is particle collision and aggregation.

* Particle collision works

* Added gui

* Some minor adjustments

* Added the two new demos to the list of examples

In the actions array of the Path, the last elements of the args array
need to be the x and y of the last point of the segment added to the
path.
Not the case with splineThru => cause an exception if you add an other
segment after the pline (without a moveTo).
Used the same trick as absellipse does.

the updateArcLengths in CurvePath must clear the local cache,
cacheLengths

Add Mesh.copy() to fix this.

white space and a few method tags

Inherited material is overwritten if 'usemtl' declaration is encountered after the object starts but prior to next object start.
Exception to this is when faces have been declared to the inherited material, to keep MultiMaterial in sync.

Fixes #8792 and #8871.

pedant mode on.

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

* First functional change

* Better HSL to RGB function

* Correct Padding

* HSL to RGB bad colors generation, fixed

* animation to animator keyframe variable name

* golden ratio align and descriptions

* text to description

* play with computed offset negative timeScale animation

* clampWhenFinished only for non-loop animations