Adding --node_list option

[serialh0bbyist]

Adding the option to manually specify a list of nodes to run catalog diffs against.

[DLeich]

Throwing my 👍 on this idea. Would love to use it.

[jeffbyrnes]

Slightly more Rubyish way to write this (and also easier to understand if/else instead of unless/else b/c it’s not a double-negative):

nodes = if options[:node_list].nil?
          Puppet::CatalogDiff::SearchFacts.new(args).find_nodes(options)
        else
          options[:node_list].split(',')
        end

[serialh0bbyist]

Good call!