Change force_dhcp_release default to True

[OpenStack Infra]

https://review.openstack.org/36660
commit 8c5d132f2f1e8bebd8f167b46d5155134bd6a78c
Author: Joe Gordon <email address hidden>
Date: Thu Jul 11 10:31:51 2013 +0100

    Change force_dhcp_release default to True

    Historically it was was false because it requires the dnsmasq binary
    'dhcp_release' which was not present in all distros.

    Related to bug 970893

    DocImpact

    Change-Id: I4975d85a66fb930d6a56900dd569cec2a1874439

[OpenStack Infra (hudson-openstack)]

Fix proposed to branch: master
Review: https://review.openstack.org/37288

[OpenStack Infra (hudson-openstack)]

Reviewed: https://review.openstack.org/37288
Committed: http://github.com/openstack/openstack-manuals/commit/2010081abc520ae17e1ee4976659b8e9b0a1384b
Submitter: Jenkins
Branch: master

commit 2010081abc520ae17e1ee4976659b8e9b0a1384b
Author: Stephen Gordon <email address hidden>
Date: Tue Jul 16 12:51:49 2013 -0400

    Bug # 1200232 - force_dhcp_release now defaults to True.

    Historically it was was False because it requires the dnsmasq binary
    'dhcp_release' which was not present in all distributions. Most
    content and sample files already recommended setting the value to
    True, I have updated the few instances I found where it seemed
    applicable to highlight that True is now the default. I did leave one
    mention where it is recommended to set False for RHEL 6.2 because this
    is still the case.

    There is probably a wider discussion needed there about whether
    at this point we should recommend >= RHEL 6.3 or even 6.4 for
    Grizzly/Havana as it significantly improves the availability of
    packages for a number of issues like this).

    Change-Id: Ief819e1d3366ee1e1cd42f6bd8b61eaf7c20401d
    Fixes: bug 1200232