runcode: improved UI, in-game support, JS support

resources/runcode/runcode.js

@@ -0,0 +1,11 @@
+exports('runJS', (snippet) => {
+    if (IsDuplicityVersion() && GetInvokingResource() !== GetCurrentResourceName()) {
+        return [ 'Invalid caller.', false ];
+    }
+
+    try {
+        return [ new Function(snippet)(), false ];
+    } catch (e) {
+        return [ false, e.toString() ];
+    }
+});