Adding example snippets for 2D Primatives.
Formatted 2D Primatives examples, added Attributes examples.
Added example snippets for Curves.
Added example snippets for Vertex.js.
Removing references to P3D.
Merge branch 'master' into derek

Conflicts:
	docs/yuidoc-p5-theme/assets/js/reference.js
	docs/yuidoc-p5-theme/assets/js/reference.js.map
	lib/p5.js
	lib/p5.min.js
Merge branch 'master' into derek

Conflicts:
	lib/p5.js