Support for import as module, wabac.js 2.20 (#364)

- Extensibility for AWP (customizable toolbar, pass replay iframe messages to parent)
- Support export as module, build separate index.js for module in addition to ui.js
- Update to wabac.js 2.20.0
- bump to 2.2.0

tsconfig.eslint.json

@@ -4,5 +4,5 @@
   },
   "extends": "./tsconfig.json",
   "include": ["**/*.ts", "**/*.js", ".*.js"],
-  "exclude": ["__generated__", "__mocks__", "dist", "ruffle/*.js"]
+  "exclude": ["dist", "scratch"]
 }