JSON Material format 4

Work in progress.

Example of MeshPhongMaterial

{
	"metadata": {
		"version": 4.2,
		"type": "material",
		"generator": "MaterialExporter"
	},
	"type": "MeshPhongMaterial",
	"color": 16777215,
	"ambient": 16777215,
	"emissive": 0,
	"specular": 1118481,
	"shininess": 30,
	"opacity": 1,
	"transparent": false,
	"wireframe": false
}