Beginning to refactor the editor before reimplementing history.

src/common/graph/graph.ts

src/display/renderer.tsx

src/editor/components/historynavigator.tsx

src/editor/components/instructions.tsx

src/editor/components/nodedetails.tsx

src/editor/components/selectlayer.tsx

src/editor/components/settings.tsx

src/editor/editor.tsx

src/editor/renderer.tsx