Add async executor

src/main/java/io/akarin/server/core/AkarinAsyncExecutor.java

@@ -0,0 +1,42 @@
+package io.akarin.server.core;
+
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
+
+import net.minecraft.server.MinecraftServer;
+
+public class AkarinAsyncExecutor extends Thread {
+    private final static Logger LOGGER = LogManager.getLogger("Akarin"); 
+    
+    public static AkarinAsyncExecutor initalise() {
+        return Singleton.instance;
+    }
+    
+    private static class Singleton {
+        private static final AkarinAsyncExecutor instance;
+        
+        static {
+            instance = new AkarinAsyncExecutor();
+            instance.setName("Akarin Slack Scheduler Thread");
+            instance.setDaemon(true);
+            instance.start();
+            LOGGER.info("Async executor started");
+        }
+    }
+    
+    @Override
+    public void run() {
+        MinecraftServer server = MinecraftServer.getServer();
+        
+        while (server.isRunning()) {
+            
+            
+            try {
+                Thread.sleep(100);
+            } catch (InterruptedException interrupted) {
+                continue;
+            }
+        }
+    }
+    
+}

src/main/java/net/minecraft/server/MinecraftServer.java

@@ -1871,7 +1871,7 @@ public abstract class MinecraftServer implements IAsyncTaskHandler, IMojangStati
     }
 
     // CraftBukkit start
-    @Deprecated
+    //@Deprecated // Akarin - remove deprecated
     public static MinecraftServer getServer() {
         return SERVER;
     }