Refactored for Icehouse RC1

* Enabled IPv6 forwarding
* Changed Icehouse Repository URL
* Removed old (2.59) and added new (2.68) dnsmasq
* refactored Keystone Commands (e.g. --user_id changed to --user)
* installed linux-headers
* Disabled "db_enforce_mysql_charset" - see Bug #1301036 in OpenStack
* Clear nova.conf on controller and just add [DEFAULT] section before writing to it