Cache some accessor results
Cache some accessor results

This may be overkill, but I don't think it's *theoretically* overkill;
we call non-inline functions in between these accessor calls and so
even though we can be sure the results haven't changed, the compiler
probably can't.

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