readFiles now handles DT_UNKNOWN

Implements simple handling for d_type DT_UNKNOWN (always returned by readdir() on my platform (jfs))

http://man7.org/linux/man-pages/man3/readdir.3.html
"Currently, only some filesystems (among them: Btrfs, ext2, ext3, and ext4) have full support for returning the file type in d_type. All applications must properly handle a return of DT_UNKNOWN."