reverted the previous change, acknowledging 06a0a15a (comment 323821)

This reverts commit 3066894e.

This reverts commit 7b6d5993.

Revert "removed useless lines from the patch Support-syslog-less.patch, when only spaces were touched"

This reverts commit 1523fb41.

fix pam_group testing

See merge request debian/cron!5

This reverts commit b3ff6b4e.

grouped the two tests which are waiting for a crontab job in the same file, so there is one single delay

moved debian/cron.postrm to debian/cron-daemon-common.postrm, and added a condition (systemd-cron not installed) to let it remove /etc/cron.allow and /etc/cron.deny)

send stderr to /dev/null when installinf cron, to prevent the failure caused by the message "delaying package configuration, since apt-utils is not installed"