Skip 3694 warnings on trivial resource cloning

Turns the 3694 warning into a debug message if the prior resource is
identical to the current resource.  Suggestion for opscode/chef-rfc#76
No that'd just be `:@version` and `:@command`.  Really it looks like `:@params` is internally unused and just there to have something to set in the DSL.  Its very odd and I wonder if we couldn't just figure out a way to rip it out (it does explode in the DSL when you try to rip it out of the resource though, I did check that).