* Update comment for defineFunction handler.
* Rename .value to .text in all token-style ParseNodes.
* Rename symbolNode's .value to .text.
* Rename color-token's .value to .color.
* Define the nested version of ParseNodes structs explicitly.
Passes test:jest, but fails test:flow.
* Fix additional type errors reported by flow.
* Migrate rebased code from master.
* Rename ParseNode.js to parseNode.js.
* Update defineEnvironment output type to fix the flow errors in environment/array.js.