distro/redhat: Update to support CentOS/RHEL/Fedora, upstart/init/systemd

* redhat/quagga.spec.in: Update to support CentOS, RHEL and Fedora, and
  support the various init systems across different versions of these
  distros, e.g.  upstart/init/systemd.

  Clean up various warnings from rpmlint.

  Remove configure options that are gone.

A few edits and commit message by:
Paul Jakma <paul.jakma@hpe.com> / <paul@jakma.org>
diff --git a/redhat/Makefile.am b/redhat/Makefile.am
index 4e99855..fadfe64 100644
--- a/redhat/Makefile.am
+++ b/redhat/Makefile.am
@@ -3,4 +3,6 @@
 	isisd.service ospf6d.init ospf6d.service ospfd.init ospfd.service \
 	quagga.logrotate quagga.pam quagga.spec \
 	quagga.sysconfig ripd.init ripd.service ripngd.init ripngd.service \
-	watchquagga.init pimd.init pimd.service zebra.init zebra.service
+	watchquagga.init pimd.init pimd.service zebra.init zebra.service \
+	README.rpm_build.md
+