Add files to UDF 1.02

[HT-7]

The mkudffs tool can create blank UDF 1.02 images, but there appears to be no way to add files to them, since UDF 1.02 can only be written to sequentially.

Please add something like an --add-files option. Obviously, the mtime (last modified time) and ctime (last inode changed time) should be retained, for both files and folders.

Example:

mkudffs -r 1.02 --new-file example.img 1000 --add-files "folder 1" "example.mp4" "example2.mp4"

(1000 is block count of the file system.)