Add spyOnAllFunctions function

This function will spy on all writable and configurable functionss of
an object that is passed in. It can be used like this:

    spyOnAllFunctions(obj);

This commit addresses https://github.com/jasmine/jasmine/issues/1421

src/core/SpyRegistry.js

@@ -120,6 +120,23 @@ getJasmineRequireObj().SpyRegistry = function(j$) {
       return spy;
     };
 
+    this.spyOnAllFunctions = function(obj) {
+      if (j$.util.isUndefined(obj)) {
+        throw new Error('spyOnAllFunctions could not find an object to spy upon');
+      }
+
+      for (var prop in obj) {
+        if (Object.prototype.hasOwnProperty.call(obj, prop) && obj[prop] instanceof Function) {
+          var descriptor = Object.getOwnPropertyDescriptor(obj, prop);
+          if ((descriptor.writable || descriptor.set) && descriptor.configurable) {
+            this.spyOn(obj, prop);
+          }
+        }
+      }
+
+      return obj;
+    };
+
     this.clearSpies = function() {
       var spies = currentSpies();
       for (var i = spies.length - 1; i >= 0; i--) {

src/core/requireInterface.js

@@ -235,6 +235,18 @@ getJasmineRequireObj().interface = function(jasmine, env) {
       return env.spyOnProperty(obj, methodName, accessType);
     },
 
+    /**
+     * Installs spies on all writable and configurable properties of an object.
+     * @name spyOnProperty
+     * @function
+     * @global
+     * @param {Object} obj - The object upon which to install the {@link Spy}s
+     * @returns {Object} the spied object
+     */
+    spyOnAllFunctions: function(obj) {
+      return env.spyOnAllFunctions(obj);
+    },
+
     jsApiReporter: new jasmine.JsApiReporter({
       timer: new jasmine.Timer()
     }),