Update installation guide for Juno release

I updated the installation guide for Juno release packages as
follows:

1) Converted 'systemctl' commands to single lines.
2) Converted more sections to use 'systemctl' commands.
3) Added note about lengthy installation time for
   'openstack-selinux' package.
4) Explicitly configured UUID tokens and SQL driver in
   keystone. RDO needs to update or remove the 'dist'
   configuration files for services.
5) Explicitly configured local file system store options
   in [glance_store] section that appeared two days before
   official release. Although the Ubuntu and RDO packages
   appear to work by default, late changes to configuration
   files tend to cause problems at some point.
6) Explicitly configured authentication strategy to keystone
   in nova on controller and compute nodes. I think we should
   avoid relying on defaults for this option and reconsider
   for Kilo, particularly with RDO packages.
7) Explicitly installed 'sysfsutils' package on nova compute nodes
   because nova looks for it during cinder volume operations.
8) Removed explicit installation of 'ipset' package on neutron
   network and compute nodes because the Ubuntu and RDO packages
   install it as a dependency. Not sure about SUSE, so I left
   the explicit installation.
9) Changed cinder example devices from /dev/sdb to /dev/sdb1
   because LVM on CentOS didn't like the former.

Note: The configuration changes mostly apply to RDO packages on
CentOS, but given the time constraints, I fixed some other issues.
Also, this patch ignores the sahara chapter.

Closes-Bug: #1383925

Change-Id: I0c9bbbfe72b8f0358f00d4f82b90ce4976a90ea2
Merge "Update installation guide for Juno release"