packaging: engine-service: downstream infrastructure usage

Use features of downstream instead our own implementation.

systemd

1. detach from controlling terminal.
2. Change user/group.
3. stop service using signal.
4. set rlimit.

sysv

1. Change user/group.
2. stop service by pidfile.
3. set rlimit

systemd note:

As jboss return non zero error code when receiving SIGTERM, and systemd
expect processes to terminate with zero error code, we create a wrapper
over the java.

Change-Id: Ie02f0d44bbba7d1a7af6bcf6b808610e85b907c6
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>