Compatibility with IE11 (#592)

I have some Problems with the old implementation under IE11, it throw Exceptions and/or produce unwanted behavior in other JS (eg JQuery).

src/utils.js

@@ -1,24 +1,47 @@
 if (!Array.prototype.find) {
-    Array.prototype.find = function(predicate) {
-        if (this === null) {
-            throw new TypeError('Array.prototype.find called on null or undefined')
-        }
-        if (typeof predicate !== 'function') {
-            throw new TypeError('predicate must be a function')
-        }
-        var list = Object(this)
-        var length = list.length >>> 0
-        var thisArg = arguments[1]
-        var value
-
-        for (var i = 0; i < length; i++) {
-            value = list[i]
-            if (predicate.call(thisArg, value, i, list)) {
-                return value
-            }
+  Object.defineProperty(Array.prototype, 'find', {
+    value: function(predicate) {
+      // 1. Let O be ? ToObject(this value).
+      if (this == null) {
+        throw TypeError('"this" is null or not defined');
+      }
+
+      var o = Object(this);
+
+      // 2. Let len be ? ToLength(? Get(O, "length")).
+      var len = o.length >>> 0;
+
+      // 3. If IsCallable(predicate) is false, throw a TypeError exception.
+      if (typeof predicate !== 'function') {
+        throw TypeError('predicate must be a function');
+      }
+
+      // 4. If thisArg was supplied, let T be thisArg; else let T be undefined.
+      var thisArg = arguments[1];
+
+      // 5. Let k be 0.
+      var k = 0;
+
+      // 6. Repeat, while k < len
+      while (k < len) {
+        // a. Let Pk be ! ToString(k).
+        // b. Let kValue be ? Get(O, Pk).
+        // c. Let testResult be ToBoolean(? Call(predicate, T, « kValue, k, O »)).
+        // d. If testResult is true, return kValue.
+        var kValue = o[k];
+        if (predicate.call(thisArg, kValue, k, o)) {
+          return kValue;
         }
-        return undefined
-    }
+        // e. Increase k by 1.
+        k++;
+      }
+
+      // 7. Return undefined.
+      return undefined;
+    },
+    configurable: true,
+    writable: true
+  });
 }
 
 if (typeof window !== 'undefined' && typeof window.CustomEvent !== "function") {