add engine and frame apis for enabling threading and wasm

src/kiri-run/engine.js

@@ -83,6 +83,17 @@ class Engine {
         return this;
     }
 
+    setController(controller) {
+        let ctrl = this.settings.controller;
+        Object.assign(ctrl, controller);
+        if (ctrl.threaded) {
+            kiri.client.pool.start();
+        } else {
+            kiri.client.pool.stop();
+        }
+        return this;
+    }
+
     setTools(tools) {
         this.settings.tools = tools;
         return this;

src/kiri-run/frame.js

@@ -63,6 +63,8 @@
 
         setFeatures: (features) => { send({ features })},
 
+        setController: (controller) => { send({ controller })},
+
         slice: () => { send({ function: "slice", callback: true }) },
 
         prepare: () => { send({ function: "prepare", callback: true }) },