v2 Enable local development (#52)

- Create local dev environment
- Add gas-client and google-apps-script-webpack-dev-server packages for development
- Add dev/ wrapper app
- Update webpack config to support development environment
- Redesigned READMEs
- Support typescript
- Update npm scripts
- Organize and update .gitignore file
- Add .vscode settings for clasp files
- Remove tracking for files in dist/

.vscode/settings.json

@@ -0,0 +1,13 @@
+{
+  "json.schemas": [{
+      "fileMatch": [
+          "appsscript.json"
+      ],
+      "url": "http://json.schemastore.org/appsscript"
+  }, {
+      "fileMatch": [
+          ".clasp.json"
+      ],
+      "url": "http://json.schemastore.org/clasp"
+  }]
+}