docs($state): document 'parent' parameter

Author: christopherthielen

src/state.js

@@ -445,6 +445,13 @@ function $StateProvider(   $urlRouterProvider,   $urlMatcherFactory) {
    *   published to scope under the controllerAs name.
    * <pre>controllerAs: "myCtrl"</pre>
    *
+   * @param {string|object=} stateConfig.parent
+   * <a id='parent'></a>
+   * Optionally specifies the parent state of this state.
+   *
+   * <pre>parent: 'parentState'</pre>
+   * <pre>parent: parentState // JS variable</pre>
+   *
    * @param {object=} stateConfig.resolve
    * <a id='resolve'></a>
    *
@@ -476,15 +483,19 @@ function $StateProvider(   $urlRouterProvider,   $urlMatcherFactory) {
    *   transitioned to, the `$stateParams` service will be populated with any 
    *   parameters that were passed.
    *
+   *   (See {@link ui.router.util.type:UrlMatcher UrlMatcher} `UrlMatcher`} for
+   *   more details on acceptable patterns )
+   *
    * examples:
    * <pre>url: "/home"
    * url: "/users/:userid"
    * url: "/books/{bookid:[a-zA-Z_-]}"
    * url: "/books/{categoryid:int}"
    * url: "/books/{publishername:string}/{categoryid:int}"
    * url: "/messages?before&after"
-   * url: "/messages?{before:date}&{after:date}"</pre>
+   * url: "/messages?{before:date}&{after:date}"
    * url: "/messages/:mailboxid?{before:date}&{after:date}"
+   * </pre>
    *
    * @param {object=} stateConfig.views
    * <a id='views'></a>