WebGL illustration of new membrane / object graphs model

[ajvincent]

To do:

• [x] Dummy HTML-like object graphs (static), with "wet" DOM nodes and a "dry" event listener
• [x] Spheres drawn for the original objects
• [x] Planes drawn for the object graphs
• [x] Lines drawn for connecting nodes in object graphs
• [x] Solid circles drawn where spheres intersect planes
• [x] Text superimposed to label nodes, object graphs
• [x] Rotating the membrane illustration to show multiple object graphs
• [x] Cylinders drawn perpendicular to planes for relationships between objects and proxies
• [x] Wireframe hemispheres for proxies with flat edges aimed at original objects
• [ ] Transition inserting a new object graph
• [ ] Explanatory text coordinated with rendered graphics

[ajvincent]

docs/concepts/model.html

[ajvincent]

[ajvincent]

Closing this out: the remaining tasks (text & transition) will be part of #184.