Improve error message when an invalid order is selected for the Lagrange FE family.
Improve error message when an invalid order is selected for the
Lagrange FE family.

Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh,Mbewu/libmesh