Add debug messages for region undo debugging

BauSystem_15/src/de/steamwar/bausystem/utils/FlatteningWrapper15.java

@@ -213,6 +213,7 @@ public class FlatteningWrapper15 implements FlatteningWrapper {
             start("operation");
             Operations.completeBlindly(ch.createPaste(e).to(v).ignoreAirBlocks(pasteOptions.isIgnoreAir()).build());
             System.out.println("Operation: " + stop("operation"));
+            System.out.println("ChangeSet: " + e.getChangeSet());
             return e;
         } catch (WorldEditException e) {
             throw new SecurityException(e.getMessage(), e);

BauSystem_Main/src/de/steamwar/bausystem/region/Region.java

@@ -484,6 +484,7 @@ public class Region {
         } else {
             editSession = paste(tempFile, pastePoint, pasteOptions);
         }
+        System.out.println("ChangeSet2: " + editSession.getChangeSet());
 
         initSessions();
         undoSessions.push(editSession);
@@ -508,6 +509,7 @@ public class Region {
             if (session == null) {
                 return false;
             }
+            System.out.println("ChangeSet3: " + session.getChangeSet());
             session.undo(session);
             redoSessions.push(session);
             return true;