render shape when associated text is hovered

[tmpvar]

• [x] associated text with execution via (new Error()) magic
• [x] track mousemove and render the appropriate shape
• [x] separate the helper meshes out from the display meshes
• [x] handle multiple calls in the same location (loops)

[tmpvar]

it is now possible to view the different states of operations:

var end = sphere(20).cut(cylinder(10, 200).rotate(90, 0, 90))
display(end);

no hover

hover over the rotated cylinder

hover over the base cylinder

awesome!

[tmpvar]

[tmpvar]

I think that is good enough for now, tracking extra work in new tickets