title: PyCharm type hinting: return type not detected
body: <p>I want to add type hinting to PyCharm, but PyCharm does not detect the return type if I use <code>cached_property</code> instead of <code>property</code>.</p>
  
  <pre><code>class MyClass(object):
  
      #@cached_property # does not work
      @property         # works
      def foo_client(self):
          '''
          @rtype foo.Client
          '''
          return client_getter(...)
  </code></pre>
  
  <p>Usage:</p>
  
  <pre><code>my_class = MyClass()
  my_class.foo_client.HERE_I_WANT_AUTOCOMPLETE
  </code></pre>
  
  <p>I use <code>cached-property==1.1.0</code> and PyCharm 4.5.</p>