Move SendFileToUser to TSP.SendFileTextAsMessage.

This is not a great method, but it's actually the only method in TShock
that interpolates the %map% and %players% variables and it used in at
least three places in the codebase. Since it's already so specialized,
it's not worth changing it to take an actual File object, in my humble
opinion.

This also clarifies what the method does and what makes it special, as
opposed to being fairly generic.

TShockAPI/TSPlayer.cs

@@ -1458,6 +1458,43 @@ namespace TShockAPI
 			SendDataFromPlayer(PacketTypes.SmartTextMessage, ply, msg, red, green, blue, -1);
 		}
 
+		/// <summary>
+		/// Sends the text of a given file to the player. Replacement of %map% and %players% if in the file.
+		/// </summary>
+		/// <param name="file">Filename relative to <see cref="TShock.SavePath"></see></param>
+		public void SendFileTextAsMessage(string file)
+		{
+			string foo = "";
+			bool containsOldFormat = false;
+			using (var tr = new StreamReader(file))
+			{
+				Color lineColor;
+				while ((foo = tr.ReadLine()) != null)
+				{
+					lineColor = Color.White;
+					if (string.IsNullOrWhiteSpace(foo))
+					{
+						continue;
+					}
+
+					var players = new List<string>();
+
+					foreach (TSPlayer ply in TShock.Players)
+					{
+						if (ply != null && ply.Active)
+						{
+							players.Add(ply.Name);
+						}
+					}
+
+					foo = foo.Replace("%map%", (TShock.Config.UseServerName ? TShock.Config.ServerName : Main.worldName));
+					foo = foo.Replace("%players%", String.Join(",", players));
+
+					SendMessage(foo, lineColor);
+				}
+			}
+		}
+
 		/// <summary>
 		/// Wounds the player with the given damage.
 		/// </summary>