Changes in distributed_vector.C for -Wshadow.

Issue #24.
Changes in distributed_vector.h for -Wshadow.

Issue #24.
Changes in laspack_matrix.C for -Wshadow.

Issue #24.
Changes in laspack_vector.C for -Wshadow.

Issue #24.
Changes in petsc_vector.C for -Wshadow.

Issue #24.
Changes in petsc_matrix.C for -Wshadow.

Issue #24.
Changes in type_tensor.C for -Wshadow.

Issue #24.
Changes in quadrature.C for -Wshadow.

Issue #24.
Making ExodusII reader recognize more types of elements.

Do case-insensitive comparisons only.

This has been tested with output meshes from Cubit.

Adding shell types, although cubit would only write out shells for quads.
For TRISHELL, TRISHELL3, and TRISHELL6 cubit just wrote out TRIs...