Project restructure, Added .Net Core support, Fixed some bugs

src/Discord.Net.Commands/CommandBuilder.cs

@@ -0,0 +1,32 @@
+using System;
+using System.Threading.Tasks;
+
+namespace Discord
+{
+	public sealed class CommandBuilder
+	{
+		private readonly DiscordBotClient _client;
+		private readonly string _prefix;
+		private readonly bool _useWhitelist;
+
+		public CommandBuilder(DiscordBotClient client, string prefix, bool useWhitelist = false)
+		{
+			_client = client;
+			_prefix = prefix;
+			_useWhitelist = useWhitelist;
+        }
+
+		public void AddCommandGroup(string cmd, Action<CommandBuilder> config, bool useWhitelist = false)
+		{
+			config(new CommandBuilder(_client, _prefix + ' ' + cmd, useWhitelist));
+		}
+		public void AddCommand(string cmd, int minArgs, int maxArgs, Action<DiscordBotClient.CommandEventArgs> handler, bool? useWhitelist = null)
+		{
+			AddCommand(cmd, minArgs, maxArgs, e => { handler(e); return null; }, useWhitelist);
+		}
+		public void AddCommand(string cmd, int minArgs, int maxArgs, Func<DiscordBotClient.CommandEventArgs, Task> handler, bool? useWhitelist = null)
+		{
+			_client.AddCommand(cmd != "" ? _prefix + ' ' + cmd : _prefix, minArgs, maxArgs, handler, useWhitelist ?? _useWhitelist);
+		}
+	}
+}