Rewrite genisoimage mangling code to be much simpler.
Rewrite genisoimage mangling code to be much simpler.

It is easier to understand this way.

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

clalancette/pyiso,clalancette/pycdlib