It does not used if line contains the only segment

Removes `webgl2_sandbox` example from the list, see #11363.

Such method can be used directly at the end of rendering loop

Dealing with global pollution

While SVG is text format, 10-digits for each coordinate is overkill. In
many cases on can use precion=1 or even precision=0. For instance,
instead of 
path
d="M95.67875432291896,61.48774395485388L99.22967055503229,-179.38931463976644"

one gets (with precision 1)

path d="M95.7,61.5L99.2,-179.4"

This significantly (factor 2) reduces size of SVG when stored into the
file. 

Avoid explicit usage of fill-opacity or stroke-opacity
One could provide similar function in THREE.Color object itself

When SVG stored into the file, reduces file size by ~5%

If several svg:path with same style should be created, just concatenate
there 'd' attributes and make single svg:path node. Will highly reduce
size of SVG if many elements with similar color should be rendered.

Now rendering of all elements done with svg:path

Replace it by svg:rect

Idea to use svg:path for all SVG primitives.
Later one can concatenate svg:path if they have identical styles