Bumping Ubuntu 12.04 ISOs to Ubuntu 12.04.5
Bump Docker version to 1.20 (always use Docker deb packages)
Downgrading Ubuntu 12.04 desktop to 12.04.4, libgdk-pixbuf2.0-0 fails install
Adding version check for Packer to Makefile
Reverting ubuntu1204-desktop to 12.04.4
Fixing tabs for build machine Makefile
Moving files to CDN bucket