Updated reference channel entities

ref/Entities/Channels/IChannel.cs

@@ -1,17 +1,22 @@
 using System.Collections.Generic;
+using System.Threading.Tasks;
 
 namespace Discord
 {
-    public interface IChannel : IModel<ulong>
+    public interface IChannel : IEntity<ulong>
     {
-        DiscordClient Client { get; }
-        
+        /// <summary> Gets the type flags for this channel. </summary>
         ChannelType Type { get; }
+        /// <summary> Gets whether this is a text channel. </summary>
         bool IsText { get; }
+        /// <summary> Gets whether this is a voice channel. </summary>
         bool IsVoice { get; }
+        /// <summary> Gets whether this is a private channel. </summary>
         bool IsPrivate { get; }
+        /// <summary> Gets whether this is a public channel. </summary>
         bool IsPublic { get; }
-        
-        IEnumerable<User> Users { get; }
+
+        /// <summary> Gets a collection of all users in this channel. </summary>
+        Task<IEnumerable<User>> GetUsers();
     }
 }