title: bootbox.dialog compile error in TypeScript
body: <p>I'm trying to user <code>Bootbox</code> Custom Dialog with <code>bootbox.d.ts</code>. It fails to compile.</p>
  
  <pre><code>bootbox.dialog({
    message: "I am a custom dialog",
    buttons: {
      success: {
        label: "Success!",
        className: "btn-success",
        callback: function() {
          Example.show("great success");
        }
      },
      danger: {
        label: "Danger!",
        className: "btn-danger",
        callback: function() {
          Example.show("uh oh, look out!");
        }
      },
      main: {
        label: "Click ME!",
        className: "btn-primary",
        callback: function() {
          Example.show("Primary button");
        }
      }
    }
  });
  </code></pre>
  
  <p>Error:</p>
  
  <blockquote>
    <p>Error 49  Supplied parameters do not match any signature of call
    target:   Could not apply type 'string' to argument 1 which is of type
    '{ message: string; buttons: { cancel: { label: string; className:
    string; }; confirmDelete: { label: string; className: string;
    callback: () => void; }; }; }'.</p>
  </blockquote>
  
  <p>bootbox.d.ts:</p>
  
  <pre><code>interface BootboxStatic {
      alert(message: string, callback: () =&gt; void): void;
      alert(message: string, customButtonText?: string, callback?: () =&gt; void): void;
      confirm(message: string, callback: (result: boolean) =&gt; void): void;
      confirm(message: string, cancelButtonText?: string, confirmButtonText?: string, callback?: (result: boolean) =&gt; void): void;
      prompt(message: string, callback: (result: string) =&gt; void, defaultValue?: string): void;
      prompt(message: string, cancelButtonText?: string, confirmButtonText?: string, callback?: (result: string) =&gt; void, defaultValue?: string): void;
      dialog(message: string, handlers: BootboxHandler[], options?: any): void;
      dialog(message: string, handler: BootboxHandler): void;
      dialog(message: string): void;
      hideAll(): void;
      animate(shouldAnimate: boolean): void;
      backdrop(backdropValue: string): void;
      classes(customCssClasses: string): void;
      setIcons(icons: BootboxIcons): void;
      setLocale(localeName: string): void;
      addLocale(localeName: string, translations: BootboxLocale) : void;
  }
  </code></pre>
  
  <p>How can I modify the definitions to accept the dialog with the parameter I'm using?</p>