Adding Pyramid14 element.

Partial checklist for implementing new geometric element types:
* second_order_equivalent_type()
* n_second_order_adjacent_vertices()
* second_order_adjacent_vertex()
* Elem::build() case
* Elem::type_to_n_nodes_map
* Elem::type_to_n_sides_map
* Elem::type_to_n_edges_map
* first_order_equivalent_type()
* n_nodes()
Updating Makefile.am's
Ran boostrap.
Adding PYRAMID14 basis functions.
Adding first derivatives for PYRAMID14.
Adding second derivatives for PYRAMID14.
Add PYRAMID14 to all relevant branches in build_cube().

The actual work of converting to second order will be
done in the call to all_second_order().
Add support for writing 14-node pyramid elements to Exodus files.

This is pretty trivial, because Exodus doesn't really care how many
nodes a given type of element has... you just have to tell it.

Paraview, on the other hand, does not seem to be capable of displaying
these elements properly... if Paraview does display 13-node pyramids
properly, maybe a workaround would be to display 14-node pyramids by
omitting a single point?
Updating documentation with what I've found about the PYRAMID14 element
thus far.
Adding PYRAMID14 support in miscellaneous places:
* string_to_enum()
* Various functions in fe_lagrange.C
* Quadrature initialization routines
* FEAbstract::on_reference_element()
* lagrange_nodal_soln() helper function
* FEAbstract::get_refspace_nodes()
* FEInterface::max_order()
* l2_lagrange_n_dofs()
* monomial_n_dofs()
* xyz_n_dofs()
* Quality::valid()
* ElementTypes::basic_name()
* ElementTypes::name()
* QGrid::init_3D()

Not sure that I've found all of them, but these were enough
to allow me to use the PYRAMID14 in a simple finite element
calculation.
Adding one_pyramid14.xda reference element file.

Regenerated the reference_elem.data file.

Adding Pyramid14 to the ReferenceElem::get() stuff.

Maple script for verifying basis functions and computing
first and second derivatives can be found here:

https://gist.github.com/jwpeterson/7819000
Merge branch 'pyramid14'