Merge branch 'master' into mc/1.12

Author: TBlueF

BlueMapBukkit/src/main/java/de/bluecolored/bluemap/bukkit/BukkitPlugin.java

@@ -39,6 +39,11 @@ public BukkitPlugin() {
 	public void onEnable() {
 		new MetricsLite(this);
 
+		//save world so the level.dat is present on new worlds
+		for (World world : getServer().getWorlds()) {
+			world.save();
+		}
+		
 		getServer().getPluginManager().registerEvents(eventForwarder, this);
 		getCommand("bluemap").setExecutor(commands);