Performance fixes for reshuffle_extents().
Performance fixes for reshuffle_extents().

It ends up being one of our most performance critical
areas, so we do various things to optimize it.  One of
these is to remove function calls, so we get rid of
a bunch of branches and speed things up.

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

clalancette/pyiso,clalancette/pycdlib