Refactor, rearrange, reimplement reactions; receive over gateway

src/Discord.Net.Core/Entities/Messages/Emoji.cs

@@ -19,6 +19,11 @@ namespace Discord
             Name = name;
         }
 
+        internal static Emoji FromApi(API.Emoji emoji)
+        {
+            return new Emoji(emoji.Id, emoji.Name);
+        }
+
         public static Emoji Parse(string text)
         {
             Emoji result;

src/Discord.Net.Core/Entities/Messages/IMessage.cs

@@ -31,8 +31,6 @@ namespace Discord
         IReadOnlyCollection<IAttachment> Attachments { get; }
         /// <summary> Returns all embeds included in this message. </summary>
         IReadOnlyCollection<IEmbed> Embeds { get; }
-        /// <summary> Returns all reactions included in this message. </summary>
-        IReadOnlyCollection<IReaction> Reactions { get; }
         /// <summary> Returns all tags included in this message's content. </summary>
         IReadOnlyCollection<ITag> Tags { get; }
         /// <summary> Returns the ids of channels mentioned in this message. </summary>

src/Discord.Net.Core/Entities/Messages/IReaction.cs

@@ -7,6 +7,6 @@ namespace Discord
 {
     public interface IReaction
     {
-        API.Emoji Emoji { get; }
+        Emoji Emoji { get; }
     }
 }

src/Discord.Net.Core/Entities/Messages/IUserMessage.cs

@@ -14,6 +14,9 @@ namespace Discord
         /// <summary> Removes this message from its channel's pinned messages. </summary>
         Task UnpinAsync(RequestOptions options = null);
 
+        /// <summary> Returns all reactions included in this message. </summary>
+        IReadOnlyDictionary<Emoji, int> Reactions { get; }
+
         /// <summary> Adds a reaction to this message. </summary>
         Task AddReactionAsync(Emoji emoji, RequestOptions options = null);
         /// <summary> Adds a reaction to this message. </summary>