title: Swift protocol property getter for bool values not accepted
body: <p>I'm trying to create a Swift protocol for the WebView class so that it can be used in Javascript. This works fine for most properties, except for a bool property. The reason is that the Obj-C getter behind the scenes is named differently (for a <code>loading: Bool</code> property the getter is <code>isLoading</code>). How can I specify such a getter in my Swift protocol?</p>
  
  <p>Here's the relevant code:</p>
  
  <pre><code>@objc protocol WebViewJSExport : JSExport {
    var mainFrame: WebFrame! { get };
    var selectedFrame: WebFrame! { get };
  
    var loading: Bool { get };
    var mainFrameURL: String! { get };
    var mainFrameDocument: DOMDocument! { get };
    var mainFrameTitle: String! { get };
  }
  </code></pre>
  
  <p>When I use this protocol in my class like this:</p>
  
  <pre><code>class WebClient: WebView, WebViewJSExport {
  }
  </code></pre>
  
  <p>I get this compiler error (with 2 details entries):</p>
  
  <blockquote>
    <p>Type 'WebClient' does not conform to protocol 'WebViewJSExport'</p>
    
    <p>Protocol requires property 'loading' with type 'Bool'</p>
    
    <p>Objective-C method 'isLoading' provided by getter for 'loading' does
    not match the requirement's selector ('loading')</p>
  </blockquote>