title: ng-model="query" not working after connecting to Firebase
body: <p>Part of a project I am working on is listing members, members companies, etc...  I used $http within my controller to connect to a JSON file to get everything wired up and test functionality. I am using ng-repeat to populate the page and ng-scope to allow visitors to search the listings.  </p>
  
  <p>Everything worked as expected until I wired up Firebase to hold the data.  Again, the data populates the page, but now my ng-model is broke and there's no way to search the listings.  My Angular skills are still being polished, to say the least, so I'm sure I am having a noob moment.  Any chance someone could take a look, I 'de be very grateful.  Here is my code.</p>
  
  <p><strong>My Controller</strong></p>
  
  <pre><code>.controller( 'AlliedCtrl', function AlliedCtrl( $scope, $firebase) {
      var ref = new Firebase("https://mybase.firebaseio.com/members");
      var sync = $firebase(ref);
      var syncObject = sync.$asObject();
      syncObject.$bindTo($scope, "members");
  });
  </code></pre>
  
  <p><strong>My HTML</strong></p>
  
  <pre><code>&lt;div class="search-sort"&gt;
                  &lt;div class="row"&gt;
                      &lt;div class="col-sm-12 col-xs-12"&gt;
                          &lt;input ng-model="query" placeholder="Search and Sort by Keyword e.g. Accounting, Law, Mobile etc..." class="small"&gt;
                      &lt;/div&gt;
                      &lt;/div&gt;
              &lt;/div&gt;
  
              &lt;table class="table table-condensed table-responsive"&gt;
                  &lt;thead&gt;
                  &lt;tr&gt;
                      &lt;th&gt;&lt;/th&gt;
                      &lt;th&gt;Member Company&lt;/th&gt;
                      &lt;th&gt;Company Description&lt;/th&gt;
                  &lt;/tr&gt;
                  &lt;/thead&gt;
                  &lt;tbody&gt;
                  &lt;tr ng-repeat="m in members | filter:query"&gt;
                      &lt;td style="width:250px"&gt;&lt;/td&gt;
                      &lt;td style="width:250px"&gt;&lt;b&gt;{{ m.company }}&lt;/b&gt;&lt;br&gt;{{ m.address }}&lt;br&gt;{{ m.address2 }}&lt;br&gt;&lt;a href="{{ m.url }}" target="_blank"&gt;{{ m.url }}&lt;/a&gt;&lt;br&gt;&lt;br&gt;{{ m.name }}&lt;br&gt;&lt;em&gt;{{ m.title }}&lt;/em&gt;&lt;br&gt;{{ m.phone }}&lt;br&gt;&lt;a mailto="{{ m.email }}"&gt;{{ m.email }}&lt;/a&gt;&lt;br&gt;&lt;br&gt;&lt;/td&gt;
                      &lt;td&gt;{{ m.description }}&lt;/td&gt;
                  &lt;/tr&gt;
                  &lt;/tbody&gt;
              &lt;/table&gt;
  </code></pre>