Removed all from ItemState and made some comment changes

Octokit/Models/Request/IssueRequest.cs

@@ -147,20 +147,14 @@ namespace Octokit
     public enum ItemState
     {
         /// <summary>
-        /// Issues that are open
+        /// Items that are open
         /// </summary>
         Open,
 
         /// <summary>
-        /// Issues that are closed
+        /// Items that are closed
         /// </summary>
-        Closed,
-
-        /// <summary>
-        /// All the issues. The option is Obsolete
-        /// </summary>
-        [Obsolete("The value is Obsolete and will be removed in a future release as it is not a valid option for Search, Create and Update operations")]
-        All
+        Closed
     }
 
     /// <summary>

Octokit/Models/Request/PullRequestRequest.cs

@@ -19,7 +19,7 @@ namespace Octokit
         }
 
         /// <summary>
-        /// "open", "closed" or "all" to filter by state. Default is "open".
+        /// Which PullRequests to get. The default is <see cref="ItemStateFilter.Open"/>
         /// </summary>
         public ItemStateFilter State { get; set; }
 

Octokit/Models/Response/Issue.cs

@@ -64,7 +64,7 @@ namespace Octokit
         public int Number { get; protected set; }
 
         /// <summary>
-        /// Whether the issue is open, closed or all.
+        /// Whether the issue is open or closed.
         /// </summary>
         public ItemState State { get; protected set; }