fix(fabController): Properly namespace FabController.

The FabController was not properly namespaced for Material Design.
Fix by adding `Md` to the beginning to ensure we do not override
users controllers.

Fixes #6881. Closes #6919.

Author: topherfangio

src/components/fabSpeedDial/fabController.js

@@ -2,9 +2,9 @@
   'use strict';
 
   angular.module('material.components.fabShared', ['material.core'])
-    .controller('FabController', FabController);
+    .controller('MdFabController', MdFabController);
 
-  function FabController($scope, $element, $animate, $mdUtil, $mdConstant, $timeout) {
+  function MdFabController($scope, $element, $animate, $mdUtil, $mdConstant, $timeout) {
     var vm = this;
 
     // NOTE: We use async eval(s) below to avoid conflicts with any existing digest loops

src/components/fabSpeedDial/fabSpeedDial.js

@@ -106,7 +106,7 @@
       },
 
       bindToController: true,
-      controller: 'FabController',
+      controller: 'MdFabController',
       controllerAs: 'vm',
 
       link: FabSpeedDialLink

src/components/fabToolbar/fabToolbar.js

@@ -84,7 +84,7 @@
       },
 
       bindToController: true,
-      controller: 'FabController',
+      controller: 'MdFabController',
       controllerAs: 'vm',
 
       link: link