gcc4*: remove bashism
replace source with . in posix sh scripts

source makes the intent and the inclusion of another script much
clearer, but it's not in POSIX and dash apparently does not support
it.
rsync: bump, pkgconf: add working mirror
Dont wait if the boot device is available
add packages to create debian images
A more reliable way of mounting /dev for the chroot
Enable cgroups in kernel