Non-relative URI in GLTF

[aWeirdo]

@bghgary answered a related question here

GLB with remote asset URLs

The sandbox works by chance. I should probably make it fail by default. The glTF spec has this to say about URIs: glTF uses URIs to reference buffers and image resources. Clients must support at least these two URI types: Data URIs … Relative URI paths — or path-noscheme as defined by RFC 3986, Section 4.2 — without scheme, authority, or parameters. Reserved characters must be percent-encoded, per RFC 3986, Section 2.2. Implementation Note: Clients can optionally support additio…