.sad, .smch now persist restarts. .usmch added to unset music channel, since destroying a player won't reset it, Added --start-delay option for .race command

NadekoBot.Core/Services/Database/Models/MusicSettings.cs

@@ -0,0 +1,11 @@
+namespace NadekoBot.Core.Services.Database.Models
+{
+    public class MusicSettings : DbEntity
+    {
+        public int GuildConfigId { get; set; }
+        public GuildConfig GuildConfig { get; set; }
+
+        public bool SongAutoDelete { get; set; } = false;
+        public ulong? MusicChannelId { get; set; } = null;
+    }
+}