Content patch import dialog & server support

core/src/mindustry/game/EventType.java

@@ -1,6 +1,7 @@
 package mindustry.game;
 
 import arc.math.geom.*;
+import arc.struct.*;
 import arc.util.*;
 import mindustry.core.GameState.*;
 import mindustry.ctype.*;
@@ -102,6 +103,15 @@ public class EventType{
     /** Called when a game begins and the world tiles are initiated. About to updates tile proximity and sets up physics for the world(Before WorldLoadEvent) */
     public static class WorldLoadEndEvent{}
 
+    /** Called when a save loads custom patches. {@link #patches} can be modified in the event handler. */
+    public static class ContentPatchLoadEvent{
+        public final Seq<String> patches;
+
+        public ContentPatchLoadEvent(Seq<String> patches){
+            this.patches = patches;
+        }
+    }
+
     public static class SaveLoadEvent{
         public final boolean isMap;