Update /say to vanilla behaviour. Fixes BUKKIT-4224

Prior to this commit all /say command output would be a generic "[Server]"
prefixed line. This commit changes that by adding the source into the
message, such as a player. By doing this Bukkit more closely matches
vanilla behaviour and gives a more descriptive message to the client.

src/main/java/org/bukkit/command/defaults/SayCommand.java

@@ -6,6 +6,7 @@
 import org.bukkit.Bukkit;
 import org.bukkit.ChatColor;
 import org.bukkit.command.CommandSender;
+import org.bukkit.command.ConsoleCommandSender;
 import org.bukkit.entity.Player;
 
 import com.google.common.collect.ImmutableList;
@@ -14,7 +15,7 @@ public class SayCommand extends VanillaCommand {
     public SayCommand() {
         super("say");
         this.description = "Broadcasts the given message as the console";
-        this.usageMessage = "/say <message>";
+        this.usageMessage = "/say <message ...>";
         this.setPermission("bukkit.command.say");
     }
 
@@ -27,20 +28,24 @@ public boolean execute(CommandSender sender, String currentAlias, String[] args)
         }
 
         StringBuilder message = new StringBuilder();
+        message.append(ChatColor.LIGHT_PURPLE).append("[");
+        if (sender instanceof ConsoleCommandSender) {
+            message.append("Server");
+        } else if (sender instanceof Player) {
+            message.append(((Player) sender).getDisplayName());
+        } else {
+            message.append(sender.getName());
+        }
+        message.append(ChatColor.LIGHT_PURPLE).append("] ");
+
         if (args.length > 0) {
             message.append(args[0]);
             for (int i = 1; i < args.length; i++) {
-                message.append(" ");
-                message.append(args[i]);
+                message.append(" ").append(args[i]);
             }
         }
 
-        if (sender instanceof Player) {
-            Bukkit.getLogger().info("[" + sender.getName() + "] " + message);
-        }
-
-        Bukkit.broadcastMessage(ChatColor.LIGHT_PURPLE + "[Server] " + message);
-
+        Bukkit.broadcastMessage(message.toString());
         return true;
     }