Fixes needed for running tests against puppet's master branch

Specifically this commit

 - Adds specific checks for puppet 3 when loading storeconfig code
   storeconfig does not work against current master and will be removed
   as part of Puppet 4.0.0. We want to maintain backward compatibility,
   so the code supports both

 - Removes references to Puppet[:trusted_node_data] when on Puppet
   4 (essentially assuming it is always true on 4). Like above we will
   look for it when on Puppet 3.y.z and ignore it (assuming true) when
   on Puppet 4.y.z
Seems a little brittle. Also, is a Puppet feature the correct thing to do here? Its just that its a brand new API touchpoint we are introducing, and the API isn't looking so stable with the major differences between 3 and 4 we have been seeing.