Debounce autobake in the web app.

Added debounce with guidance from the underscore.js implementation:
e944e0275a/underscore.js (L880)

src/core/Utils.js

@@ -1185,6 +1185,33 @@ const Utils = {
         "Latin1":  CryptoJS.enc.Latin1,
     },
 
+
+    /**
+     * A utility for "debouncing" functions.
+     * Debouncing is when you want to ensure events triggered by an event are rate-limited.
+     * @constant
+     */
+    debounce(fn, delay) {
+        let timeout;
+
+        return function() {
+            /**
+             * later calls the debounced function with arguments.
+             * If the debounced function is called again, then the timeout
+             * which calls later is cancelled.
+             */
+            let later = () => {
+                fn.apply(this, arguments);
+            };
+
+            if (timeout) {
+                clearTimeout(timeout);
+            }
+
+            timeout = setTimeout(later, delay);
+        };
+    },
+
 };
 
 export default Utils;

src/web/App.js

@@ -36,6 +36,8 @@ var App = function(categories, operations, defaultFavourites, defaultOptions) {
     this.ingId       = 0;
 
     window.chef      = this.chef;
+
+    this.autoBake = Utils.debounce(this.autoBake, 300);
 };