Initial split of the modules

NadekoBot.Core/Common/NoPublicBotPrecondition.cs

@@ -0,0 +1,18 @@
+using System;
+using System.Threading.Tasks;
+using Discord.Commands;
+
+namespace NadekoBot.Common
+{
+    public class NoPublicBot : PreconditionAttribute
+    {
+        public override Task<PreconditionResult> CheckPermissions(ICommandContext context, CommandInfo command, IServiceProvider services)
+        {
+#if GLOBAL_NADEKo
+            return Task.FromResult(PreconditionResult.FromError("Not available on the public bot"));
+#else
+            return Task.FromResult(PreconditionResult.FromSuccess());
+#endif
+        }
+    }
+}