Early dection of mispelled port name does not work with 2x2 mulit- on El Capitan

[jpvandy]

A long time ago processing was insert to induce an early seg-fault if a port name was misspelled. (This was protection against this error being encounter later in a less obvious way.) Also a test was created to verify the non-matching port was thusly detected.
Currently a bad port name does not induce a seg-fault on 2x2 multi on El Capitan.
It is not clear when a code update removed this failure, because until quite recently 2x2 on all platforms had so test failures that this low priority error wasn't noticed.

[ghost]

I do not recall ever forcing a segfault in the code. The ConfigGraph's checkForStructuralErrors should be printing a warning about invalid ports. I would be OK upgrading that warning to a Output.fatal() call.

Thoughts? ( @nmhamster @feldergast )

[nmhamster]

@bjmoor definitely would prefer an Output.fatal() call because that should handle cleanup correctly with respect to MPI etc.