Fix for load_and_allocate in regards to issue #42

load_and_allocate did not properly enter into the 'data' NVP that the
ptr_wrapper creates for unique/shared ptr.  When loading these types,
we now go through a wrapper struct to force entry into an extra node to
resolve this issue.

Changes to unittests are for an issue compiling with g++-4.7.3 under
Ubuntu where steady_clock::now() is not defined for some reason