What happens if you remove the directory that you monitor? (FIXME below)

Recursive option should rescan directory when changed?
  --rescan
  rescan directory
    for each directory that still exists, ignore
    for each directory that no longer exists, well what happens? FIXME - test
    for each directory that is new, call add_directory (FIXME: where to insert?)
    how to know what directories are old? how to search?

Add option to not replace {}? Allow escaping with backslash?
