Add tests for non-interface nil pointers.
Add tests for non-interface nil pointers.

These tests are a slight adaptation of tests provided by
kortschak@ in issue #4.  Credits go to him.

dvln/go-spew,FactomProject/go-spew,dvln/go-spew,kortschak/utter,davecgh/go-spew,bparees/go-spew,davecgh/go-spew,bparees/go-spew,FactomProject/go-spew