Return to the current folder after editing a map there

When a map in a folder is edited, and the user closes it, the interface returns to the wrong folder (ie the top level) instead of the folder you were working in. This is bloody annoying as it means you have to work on maps in the top level and basically only file them when you're finished with them. As such the folders are basically useless for organizing maps.

Folder selection should be persistent within the session.