Performance matters

Improvements:

• Add default viewpoint (#61)
• Improve performance of uniformPolyhedrons' edges (#62)
• Improve performance of coplanar polygons (#63)
• Improve performance of cones by ~6x (#64)
• Improve performance of arrows (#66)
• Improve performance of cylinders (#67)
• Add default colors to primitives and lights (#75)
• Improve performance of shaders by inlining some uniforms (#79)
• Update three.js to r137 (#80)

Documentation:

• Add more examples (#59)

Internals:

• Update minify to version 8
• Simplify lighting structs in shaders (#76)

Bug fixes:

• Correctly calculate the bounding box for primitives with scaled coordinates and radius bigger than the bounding box (#60)
• Fix cones lighting (#65)
• Scale axes ticks position (#74)