Print out NANO_CUSTOMIZE and NANO_CUSTOMIZE_LATE just
before we execute the functions listed in those variables.
It makes it a bit easier to figure out the order in which
functions are being executed during the build.
Remove unused code.
Add scripts which parse the INDEX file generated by poudriere which
has the list of ports that poudriere built. Use this information to figure
out what ports to install in the final package.
Add a knob, USE_POUDRIERE, to test building the FreeNAS ports
with poudriere.