Adds Initial Support for Grizzly High-Availability

Supports the following blueprint:
  https://blueprints.launchpad.net/openstack-cisco/+spec/ha-cloud-provisioning

1. Adds HA support to core.pp. Introduces the enable_ha
parameter for enabling the openstack-ha::controller/compute
classes.  The enable_ha parameter is only exposed to the site.pp
example file (site.pp.ha.example).

2. Adds site.pp.ha.example to serve as an example for users to
deploy COI G.2 HA.  At this time, their is significant enough
differences in top-level configuration parameters to introduce a
separate site manifest specifically for HA.

3. Add haproxy-nodes.pp that gets imported into the site manifest.
This is where server load-balancing is configured.  Users should
not need to configure this file if they use slb01/slb02 for node
names.  We may want to look at moving the configuration
parameters from haproxy-nodes.pp to a class within the opentack-ha
module in the future.

Requires the following Puppet Modules:
 puppet-augeas
 puppet-galera
 puppet-haproxy
 puppet-keepalived
 puppet-network
 puppet-openstack-ha

Requires the following Stackforge patches:
 https://review.openstack.org/#/c/41784/
 https://review.openstack.org/#/c/41817/
 https://review.openstack.org/#/c/41819/
 https://review.openstack.org/#/c/41821/
 https://review.openstack.org/#/c/39831/