Full rewrite of the network plugin

It now allows more than one server and more than one listener. It can be
configured both by parameterized class and by invoking defined types
collectd::plugin::network::server or collectd::plugin::network::listener
notify the collectd service when purging plugins

currently, if you have purge enabled and remove a plugin, the collectd service isn't notified. this should make it do that.
Merge pull request #169 from kitchen/patch-1

notify the collectd service when purging plugins
Rewrite of postgresql module to allow invocation by defined types

It now also support defining custom queries.

As a bonus, this rewrite is backward compatible (!)
Merge pull request #168 from txaj/postgresql-module-rewrite

Rewrite of postgresql module to allow invocation by defined types
Merge pull request #165 from txaj/extend-network-plugin

Full rewrite of the network plugin
Issue 164: syslog plugin needs to be loaded as first plugin

If the syslog plugin is not initialized as first plugin, other plugins
won't be able to log their startup/fail output at load time.

reported by bzed
Merge pull request #166 from txaj/syslog-loaded-first

Issue 164: syslog plugin needs to be loaded as first plugin
Add the possibility to customize package name.

For example, this add the possibility to install 'collectd-core' instead
'collectd'. Less dependencies and enough to make the collector work on
clients.
Merge pull request #170 from bdossantos/feature/custom_package_name

Add the possibility to customize package name.
Improve Varnish plugin

- Fixes bug of being unable to use module if you have no current version
  of collectd - restriction to version 5.4 would block installation when
  version is nil
- Fixes bug of ignoring configs set to false - some of these will
  default to true if they are not explicitly set to false.
- More permissive about collectd version number - the user is expected
  to know what config options are allowed in their version.
Merge pull request #171 from alphagov/improve_collectd_varnish

Improve collectd varnish
Release 3.0.0

Backwards-incompatible changes:

* Make sure plugin_conf_dir is not world readable
* Full rewrite of the network plugin
* Rewrite of postgresql module to allow invocation by defined types

Summary:

Features:

* Varnish plugin improvments
* Add the ability to customize package name.
* Add write_http plugin
* Add statsd plugin
* Add plugin logfile
* Add curl plugin
* Add support for sensors plugin
* Add support for perl plugins
* Allow custom Include directives
* Add valuesabsolute and valuespercentage to df plugin

Bugs:

* Issue 164: syslog plugin needs to be loaded as first plugin
* notify the collectd service when purging plugins
* add collectd-rrdtool package needed for RedHat
* sort python.conf options hash
Merge pull request #173 from pdxcat/release_300

Release 3.0.0
Add support for manually specifying the hostname collectd uses
Merge pull request #174 from joshgarnett/master

Add support for manually specifying the hostname collectd uses
Fix lint problems
Add Modulefile
sort snmp data and hosts hash
Set default value of chains to be hash

Seeing errors like this when value isn't set:

    Error: [] is not a Hash.  It looks to be a Array at /vagrant/dist/modules/collectd/manifests/plugin/iptables.pp:6