miscellaneous_ex9

This new example implements the thermal "film resistance" that I referred to on the list. The formulation is described in the comments at the top of miscellaneous_ex9.C. Some comments:

- I didn't know what I was supposed to do regarding Makefile.in and Makefile.am for a new example, so I omitted those files for now.

- This example won't work yet with ParallelMesh, see the TODO in AugmentSparsityOnInterface::augment_sparsity_pattern

- The code uses an N^2 algorithm to find neighboring elements on either side of the crack, based on face centroids. This could be optimized (a la @jwpeterson's sort/search code in SerialMesh::stitch_meshes) but it's not a big deal in this small example.