Ensure player data is completely saved on shutdown.

Changed shutdown data save to synchronous (from multithreaded).  Takes
longer but guarantees all data gets saved.

src/me/ryanhamshire/GriefPrevention/DataStore.java

@@ -564,6 +564,12 @@ public abstract class DataStore
 		return result;
 	}
 	
+	//saves changes to player data to secondary storage.  MUST be called after you're done making changes, otherwise a reload will lose them
+    public void savePlayerDataSync(UUID playerID, PlayerData playerData)
+    {
+        this.asyncSavePlayerData(playerID, playerData);
+    }
+	
 	//saves changes to player data to secondary storage.  MUST be called after you're done making changes, otherwise a reload will lose them
 	public void savePlayerData(UUID playerID, PlayerData playerData)
 	{

src/me/ryanhamshire/GriefPrevention/GriefPrevention.java

@@ -2226,7 +2226,7 @@ public class GriefPrevention extends JavaPlugin
 			Player player = players[i];
 			UUID playerID = player.getUniqueId();
 			PlayerData playerData = this.dataStore.getPlayerData(playerID);
-			this.dataStore.savePlayerData(playerID, playerData);
+			this.dataStore.savePlayerDataSync(playerID, playerData);
 		}
 		
 		this.dataStore.close();