revert 24deda5a and related commits

TODO

@@ -41,7 +41,6 @@ Most jobs have been converted, a few are left to do:
 
 === To be done once jenkins.d.n runs jessie
 
-* replace with bin/setsid.py workaround with setsid from the util-linux package from jessie
 * bin/g-i-installation: use lvcreate without --virtualsize
 * check if the sudo workaround in bin/g-i-installation is still needed: 'guestmount -o uid=$(id -u) -o gid=$(id -g)' would be nicer, but it doesnt work: as root, the files seem to belong to jenkins, but as jenkins they cannot be accessed.
 

bin/common-functions.sh

@@ -43,8 +43,7 @@ if [ "${0:0:5}" != "/tmp/" ] ; then
 	echo "$(date -u) - start running \"$0\" (md5sum $(md5sum $0|cut -d ' ' -f1)) as \"$TTT\" on $(hostname)."
 	echo
 	# this is the "hack": call ourself as a copy in /tmp again
-	# (setsid is not related to this hack. see commit log for 24deda5a8 it.)
-	/srv/jenkins/bin/setsid.py $TTT "$@"
+	$TTT "$@"
 	exit $?
 	# cleanup is done automatically via trap
 else

bin/setsid.py

-#!/usr/bin/python
-"""backport of util-linux' setsid -w to Debian wheezy"""
-# replace with setsid from the util-linux package from jessie (stable) or wheezy-bpo
-
-import os
-import sys
-
-if __name__ == "__main__":
-    assert len(sys.argv) > 1
-    pid = os.fork()
-    if pid == 0:
-        os.setsid()
-        os.execvp(sys.argv[1], sys.argv[1:])
-    else:
-        cpid, status = os.wait()
-        assert cpid == pid
-        sys.exit(os.WEXITSTATUS(status))