Adding Three.js Editor Scripting

[tjduigna]

We use a custom fork of the three.js repository where we maintain edits to the three.js Editor component useful for materials manipulations. The editor subdirectory includes vendored JS dependencies in a js/libs directory which are not 100% compatible with our use case.

The usage of CodeMirror in the Editor takes advantage of a TernServer for javascript autocomplete. The TernServer code refers to the ternjs module as a global. In order to support CodeMirror functionality in the Editor, we need to resolve the issue about tern being a global in the codemirror source code.

Relevant file in three.js: editor/js/Script.js

Relevant file in wave: src/components/ThreejsEditorModal.jsx