Postfix: Split TLSPol companion app into separate container (#6688)

* postfix: split postfix-tlspol service into new container

* postfix-tls-pol: added debug mode

* pf-tlspol: removed obsoleted standalone conf from Dockerfiles

* pf-tlspol: use git instead of wget

data/Dockerfiles/postfix-tlspol/stop-supervisor.sh

@@ -0,0 +1,8 @@
+#!/bin/bash
+
+printf "READY\n";
+
+while read line; do
+  echo "Processing Event: $line" >&2;
+  kill -3 $(cat "/var/run/supervisord.pid")
+done < /dev/stdin