Reorganize ext build scripts and add linting

ext/bin/lint.js

@@ -0,0 +1,13 @@
+"use strict";
+
+const { spawnSync } = require("child_process");
+const { ROOT, INCLUDE_PATH } = require("./lib/paths");
+
+
+spawnSync(`tslint --config ${ROOT}/tslint.json \
+                  --project ${ROOT}/tsconfig.json \
+                  "${INCLUDE_PATH}/**/*.ts{,x}"`
+    , {
+        shell: true
+      , stdio: [ process.stdin, process.stdout, process.stderr ]
+    });