Make Joliet directory entries spill properly.
Make Joliet directory entries spill properly.

Long ago we fixed a bug where regular ISO9660
directories could span extent boundaries, which is
not allowed by the spec.  However, we forgot the
same fix for Joliet.  Fix that here.

Signed-off-by: Chris Lalancette <281cd07d7578d97c83271fbbf2faddb83ab3791c@gmail.com>

clalancette/pyiso,clalancette/pycdlib