Add a couple of comments to resolve_ipnets__netspec().

This was originally commit 4d2317af9d18 in nsc-puppet-utils.

lib/puppet/parser/functions/resolve_ipnets.rb

@@ -64,8 +64,9 @@ module Puppet::Parser::Functions
 	# when returning a stable order; thus collect per family and remember
 	# the order we found the families in.  Then sort each family, and
 	# concatenate.
+	# NOTE: This can still break RFC 3484/6724 ordering.
 	ips = { }	# Mapping from IP family to list of addresses
-	found_families = [ ]
+	found_families = [ ]	# Order of IP families found
 	err = nil
 	wanted_families.each do |family|
 	    family = RESOLVE_IPNETS__IPFAMILIES.fetch(family)