22316 - MCO Plugin Packager produces more than one source artifact

Update Changelog
(docs) Change "node reports" to include the word "inventory;" do minor edits

The subcommand name is pretty descriptive, so let's boost its visibility. Via
suggestions from Puppet Labs support team.
Merge pull request #112 from nfagerlund/node_reports_should_be_inventory

(docs) Change "node reports" to include the word "inventory;" do minor edits
22720 - --nodes 'nodefile' doesn't work on ruby 1.9.3

In the past the nodes option failed on ruby 1.9.3 because the input
value was replacing the discovery_options array with a string.

This commit appends the input value to the discovery_options array and
adds some additional testing for the Optionparser class.