Making BrowseDir work better, now can go up a directory.  Going up to the user root is very slow since it goes into each subdir, really want that to run in separate thread.
Threading around directory parsing, now checking for more errors.  TBD need to see if absolute path of new dir is same as old, and not setString("dir",... if it is.  This is because ../../../ is valid for any number of .. once the root is reached.