CentOS 7: install `which'
Fedora Rawhide: install nodebug kernel on early stage of installation
VyOS: update 1.1.0 to 1.1.1
CentOS 7: update epel-release package version
FreeBSD: install latest virtualbox-ose-additions
OmniOS: fix the checksum for the ISO
FreeBSD: relax timing
Zero out swap partition