At this time, nglibisofs is able to output an image!! Note that communication
between writer and read thread is done via a pipe. That will be replaced by a
ring buffer in the near future.
This has to ensure that file names are unique among all files in an iso
directory. Current implementation can be improved by using a hash table
to keep the names, instead of iterate over all children. An alternative
method, keeping children sorted all the time, thus allowing binary
search, has been considered but discarded.
Current implementation support up to 9,999,999 equal files per
directory.
