Add authconfig ipav2 support

I have no idea why the GitHub merge of the pull requests causes this nasty bit of code, please only merge the code after the 2nd comment
```ruby
# Ensure we have the latest package build on the node
package 'authconfig' do
  action :install
# Ensure we have the latest package build on the node for ipav2 to work
if node['authconfig']['ipav2']['enable'] && node[:platform_version].to_i == 6
  package 'authconfig' do
    action :upgrade
  end
end
```