Return a reasonable directory for file choosers to use. If a
directory has been set using setDirectory, then use that.
Otherwise use the user's current working directory.
If all else fails, then use user's home directory. If THAT
fails, then just dump them into the root of the file system.
public void setDirectory(java.io.File file)
Set the current browsed directory to that given in the file.
public void setDirectory(java.lang.String directory)
Set the current browsed directory to that given directory. The
directory is assumed to exist.