Anyone know a good solution?
So far I have not found a better way than using File>New file and then copying contents from old file to new.
You can probably dupli
You could use "Save As..."; you'd still have to go back and re-add the original files to the project, though.
It wouldn't be such a bad way to do a bunch of related classes, though: edit file, Save As "class2", edit file, Save As "class3", etc., then "Add Existing Files" and re-add all of the files but the last to your project.