Support non-Float32, Interleaved buffer types

[gkjohnson]

Fix #10

• Adjust the "uvs-debug" page to use latest three version, use import map for example imports
• Add "#interleaved" test case for interleaved buffers in the uvs-debug page
• UVUnwrapper: Add support for non float 32 buffers, interleaved buffers

Also - an unrelated question: What's the rationale behind using this.THREE.BufferAttribute rather than importing BufferAttribute directly from the three package?