Backport basic install guide fixes from trunk

From commit 7a06cb4:
 * Add missing prompts
 * Hide the quantum-ovs-cleanup listitem for ubuntu/debian
 * Fix apache error log path
 * Fix hostnames on network node
 * Fix mysql commands for keystone database reset

From commit b51d16f:
 * Make sure to apply the sysctl settings
 * Add a note about lost iptables rules after reboot
 * Define the my_ip setting for nova nodes
 * Use the controller IP addres to access horizon

Change-Id: I75669175a45049661fc36e4db528e71cd07c64e3