Juno neutron updates

The following changes are needed to get neutron functional in Juno.

* ipset needs to be enabled in the l3 agent securitygroup section.
* conntrack needs to be installed.
* iputils-arping needs to be installed.
* policy json needs to be updated.

This PR adds all of the required changes to neutron and resolves
issue: https://github.com/rcbops/ansible-lxc-rpc/issues/276

increased sync threads

Disabled l3_ha by default.

This feature was supposed to solve for built in l3_ha in juno.
Sadly the l3_ha features is only half baked and some very serious
side effects which are reminiscent of 4.2.2. In order to maintain
stability l3_ha should be an experimental feature and only enabled
by the user when done so deliberately.

added ha dhcp agents to networks automatically

ReAdded the ATT neutron L3 ha tool.

This commit readds the neutron l3 ha tool. The att l3 ha tool
was removed in favor of native neutron l3 ha. Sadly native neutron
l3 ha is a bit of hack and does not work 100% as expected.
Add appropriate aggregate filters

The cpu_allocation_ratio and disk_allocation_ratio settings were added
previously, but do not take effect unless the matching filters are
applied.
Merge pull request #316 from nrb/ratio_filters

Add appropriate aggregate filters
Merge pull request #277 from cloudnull/juno-neutron-updates

Juno neutron updates
I think the time unit was supposed to be in seconds. If omitted, the default time unit is miliseconds, which I don't think was intended.
Merge pull request #318 from byronmccollum/haproxy-timeout-unit-master

Time Units For HAProxy Timeouts
set holland backup to minute based on container IP

- modulo 60 the container ip after casting it to an int - use this as the minute for the backup time
- set backup hour to 23
- set backup days to all
- add full path of holland binary
no need to include individual container IPs when including container cidr
Merge pull request #322 from mancdaz/master-142

no need to include individual container IPs when including container cidr in haproxy memcached whitelist
Merge pull request #321 from mancdaz/master-136

set holland backup to minute based on container IP
Templated out iscsi options in the cinder.conf

This change adds templated options for iscsi within cinder. This
change was to allow use to set sensible options within the cinder.conf
file that may be required in several different senarios.
Merge pull request #329 from cloudnull/cinder-updates

Templated out iscsi options in the cinder.conf
further refined the dynamic inventory script for multiple configs
update git_install_branches to point to head of stable/juno
Merge pull request #332 from mancdaz/master-juno-stable

update git_install_branches to point to head of stable/juno
Add check to see if a user config was loaded.

Explicitly exit if no user config is laaded.
Avoids confusing "MD5" hash of "None" error message.
Merge pull request #2 from andymcc/cloundnull-inv

Add check to see if a user config was loaded.
Merge pull request #331 from cloudnull/dynamic-inventory-confd

Dynamic inventory script updates
Change cirros image_url

Currently we pull down a source tarball for cirros, which obviously
isn't bootable.  This change points to the .img file instead.
Install lxml dependency

Running tempest smoke tests fail on all the XML tests due to lxml not
being installed in keystone containers.  The lxml package is no longer
a hard dependency since lxml is only required when using the (optional)
XmlBodyMiddleware middleware.

Ideally we'd want to remove XmlBodyMiddleware middleware since it's
being removed in Kilo, however I have not seen an option to disable all
the XML tests in tempest.