title: ui-sref params option with $state.href not working as expected
body: <p>I have a state definition like this: </p>
  
  <pre><code> $stateProvider.state('password', {
      url: '/password',
      templateUrl: 'password.html',
      controller: 'PasswordController',
      controllerAs: 'ctrl',
      params: {
          accountNumber: {
              value: null,
              squash: true
          }
      },               
  });
  </code></pre>
  
  <p>I need to reference this state with its <code>href</code> rather than using <code>ui-serif</code> directive, How can I set <code>params.accountNumber</code> inside href? </p>
  
  <p>This doesn't work:</p>
  
  <pre><code>$state.href('password', {accountNumber: $scope.accountNumber})
  </code></pre>
  
  <p>When I change this line <code>url: '/password',</code> to ` url: '/password?accoutNumber', and remove this part</p>
  
  <pre><code>params: {
      accountNumber: {
          value: null,
          squash: true
      }
  }, 
  </code></pre>
  
  <p><code>$state.href</code> works just fine.</p>