Allow user to stop a specs execution when an expectation fails

[finish #1165916] #577

src/core/errors.js

@@ -0,0 +1,10 @@
+getJasmineRequireObj().errors = function() {
+  function ExpectationFailed() {}
+
+  ExpectationFailed.prototype = new Error();
+  ExpectationFailed.prototype.constructor = ExpectationFailed;
+
+  return {
+    ExpectationFailed: ExpectationFailed
+  };
+};