Add basic online API support.

osu.Game/Online/Chat/Channel.cs

@@ -0,0 +1,32 @@
+//Copyright (c) 2007-2016 ppy Pty Ltd <contact@ppy.sh>.
+//Licensed under the MIT Licence - https://raw.githubusercontent.com/ppy/osu/master/LICENCE
+
+using System.Collections.Generic;
+using Newtonsoft.Json;
+
+namespace osu.Game.Online.Chat
+{
+    public class Channel
+    {
+        [JsonProperty(@"name")]
+        public string Name;
+
+        [JsonProperty(@"description")]
+        public string Topic;
+
+        [JsonProperty(@"type")]
+        public string Type;
+
+        [JsonProperty(@"channel_id")]
+        public int Id;
+
+        public List<Message> Messages = new List<Message>();
+
+        internal bool Joined;
+
+        [JsonConstructor]
+        public Channel()
+        {
+        }
+    }
+}