Added "context" to customize_host()
Differentiate between pkg_update() ["yum update", "apt-get upgrade"] and pkg_upgrade() ["yum upgrade", "apt-get dist-upgrade"]. Made customize_host() call pkg_upgrade() twice
Merged customize_host_stage*() into customize_host(). Added "reboot" parameter
Removed obsolete customize_host_stage*() and nilsify_host()