jenkins: Add user mode job

Signed-off-by: Pavel Emelyanov <xemul@parallels.com>
Looks-good-to-me: Andrew Vagin <avagin@virtuozzo.com>

test/jenkins/criu-user.sh

+# Make 3 iteration of dump/restore for each test
+set -e
+source `dirname $0`/criu-lib.sh
+prep
+mount_tmpfs_to_dump
+./test/zdtm.py run --all --report report --parallel 4 --user --norst -x 'maps04' || fail