[CHEF-972] resource action should have higher precedence than only_if/not_if (:nothing action)
[CHEF-972] added event dispatcher call to display messages properly
[CHEF-972] replaced only_if Conditional by a not_if Conditional
[CHEF-972] created a ConditionalAction class to be used in resource#should_skip? method
[CHEF-972] added test for checking doc formatter output when action is :nothing
[CHEF-972] replaced the CondidionalAction class by a ConditionalActionNothing class
[CHEF-972] first line of conditional_action_nothing_spec.rb with an empty comment
[CHEF-972] removed the #self.not_if method and the private constructor from ConditionalActionNothing and renamed to ConditionalActionNotNothing
[CHEF-972] fixed test unit/runner_spec.rb:379: only_if_called_times.should == 2