Add packager.py script for building snapshot pkgs
readme: Add instructions for using packager.py
validator: Use packager.py in build procedure
Rename jenkins.sh to jenkins-nightly.sh
validator: Add jenkins.sh script for non-nightlies

This script does everything the nightly build does, except for
publishing packages. It builds the packages, but does not attempt to
publish them.
validator: Clean up docs in jenkins scripts.