Add horizon_local_status_status metric

This change brings this plugin more in line w/ others where horizon
being hard down does not raise an exception but returns a metric of
horizon_local_status of 0 instead.
Update X_service_check.py plugins

This commit updates the X_service_check.py plugins to accept filtering
agent/service lists by host.  This means that we can run the plugin
multiple times per ansible hosts group and only write the necessary
metrics for that specific hosts group.

We also generalise the metric name to not include host/container name
which makes creating alarms slightly more straight-forward.

The downside to this approach is that we will end up running this
plugin a good bit more frequently, which means more nova-api hits.
Add nova_api_metadata_local_check.py script

This is a basic script to test the availability of a nova-api-metadata
service.  Unfortunately we can only get rather limited data back (in
this case, ec2 metadata versions) without specifying a bunch of headers
(such as existing IP address, etc.)

Note that I couldn't seem to get json back, so I have to parse the
string content looking for a particular version.
Merge pull request #99 from mattt416/bug_65

Update X_servi[ce_check.py plugins
Update cinder_api_local_check.py

This minor change doesn't throw a plugin error if the cinder API is
down, but rather continues on and returns a status metric of 0.  This
is more in line w/ the other plugins.
Merge pull request #101 from mattt416/update_cinder_api_local_check

Update cinder_api_local_check.py
Merge pull request #98 from mattt416/bug_63

Add horizon_local_status_status metric
Merge pull request #100 from mattt416/bug_67

Add nova_api_metadata_local_check.py script
Disk utilisation plugin.

Returns metrics for all devices listed by iostat that do not start with
'dm-'. The metric is the %util over a period of 5 seconds from when the
check is run.
Fixes #104 - consistency in formatting and units on response time message
Merge pull request #105 from stevelle/bug-104

Fixes #104 - consistency in formatting and units on response time msg
updates for 10.0.0
Merge pull request #103 from git-harry/cdm

Disk utilisation plugin.
Merge pull request #108 from mancdaz/10.0.0

updates for 10.0.0
Change uint32 ms types to double

We are dealing w/ floats here so the metric type needs to be updated
accordingly.

Closes #106
Simple script to connect to MaaS and test all checks

This script needs some work, but will form the basis of a tool to
validate that all checks (plugins) are still working after a change.
Merge pull request #109 from mattt416/add_check_test_script

Simple script to connect to MaaS and test all checks
Merge pull request #107 from mattt416/fix_types

Change uint32 ms types to double
Add Support for multiple versions of OMSA

* Add list of supported versions
* Adjust error message to reflect this
* Set checks for Start of line on Health/Status

Fixes #111
Merge pull request #113 from andymcc/master

Add Support for multiple versions of OMSA