fix issue with some sketches not being marked untitled

app/src/processing/app/Base.java

@@ -522,6 +522,7 @@ public class Base {
                          "Please save the sketch before changing the mode.",
                          null);
       } else {
+        boolean untitled = activeEditor.untitled;
         String mainPath = sketch.getMainFilePath();
 
         // save a mode file into this sketch folder
@@ -536,7 +537,10 @@ public class Base {
         handleClose(activeEditor);
 
         // re-open the sketch
-        handleOpen(mainPath, where);
+        Editor editor = handleOpen(mainPath, where);
+        if (editor != null) {
+          editor.untitled = untitled;
+        }
       }
     }
   }

todo.txt

@@ -10,8 +10,8 @@ X figure out how to suppress errors from find in build.xml
 X when changing sketchbook location, need to reload examples window
 X   and libraries, etc.. maybe just require a restart?
 X rebuilding library list, etc when changing sketchbook location
-
-_ untitled sketches not working properly (!)
+X untitled sketches not working properly
+X   empty/unmodified sketch, re-open in new mode, untitled bit not set
 
 
 regressions