Refactor TS build and fix testing

This change is largely just moving files with minor tweaks to them to fix,
the rest of the commit is build process changes:

- The addons/ and test/ dirs have been moved to src/
- The build directory has been removed
- TypeScript builds are output in out/, this is where tests are run
- The demo now relies on the dist/ build which is performed as part of ./bin/build
- Addons are now shipped under the ./build directory

tsconfig.json

@@ -3,12 +3,14 @@
     "module": "commonjs",
     "target": "es5",
     "rootDir": "src",
-    "allowJs": true
+    "allowJs": true,
+    "outDir": "out"
   },
   "exclude": [
     "addons",
     "build",
     "demo",
+    "dist",
     "out",
     "test",
     "node_modules"