packaging: spec: cleanup pre/post of services

1. cleanup ordering.
2. register sysv service.

Bug-Url: https://bugzilla.redhat.com/show_bug.cgi?id=1063873
Change-Id: I9acc51cbd9024343bb3c8ac19eab4739fe11e6fa
Signed-off-by: Alon Bar-Lev <alonbl@redhat.com>