Adding shape, first, and second derivative functions for 3D Nedelec One hex

Includes proper consistency in edge orientations (thanks to @roystgnr).
Now supporting first order NEDELEC_ONE for HEX20 and HEX27
Output now can do 2D and 3D, not just 2D.
Setting up a new example to exercise 3D Nedelec elements.
Adding vector_fe_ex3 and vector_fe_ex4 back into 'make check'.
Using direct solver for the vector FE examples.
Merge branch 'paul_nedelec'