Update KHR_materials_extension to newest draft

[tfili]

I believe the only change that is needed is removing type from the material values.

For example, this

"values": {
    "diffuse": {
        type: 35666,
        value: [0.5, 0.5, 0.5, 1]
    }
}

should be changed to this

"values": {
    "diffuse": [0.5, 0.5, 0.5, 1]
}

[tparisi]

are we removing type ? It's in the sample models...

[pjcozzi]

Yes, we plan to update the sample models by the end of the month: CesiumGS/cesium#3413 (comment)

[tparisi]

@pjcozzi OK then we'll need to update all loaders, too. e.g. Three.js. Please let me know when you update the samples and I'll do the loader.

[pjcozzi]

Will do. End of the month, latest.

[pjcozzi]

@tparisi here are the updated sample models courtesy of @tfili - #531

[pjcozzi]

@McNopper OK to close as duplicate with #947 and #945?

[UX3D-nopper]

Yes, as it is not valid anymore.