Replace exit(1) calls with queso_exit

I believe this accomplishes the goals stated in [the ticket of the same name](https://github.com/libqueso/queso/issues/1#issuecomment-23577547). 

Effort was accomplished primarily by piggybacking on the libmesh and antioch exception throwing and handling capabilities, and properly munging everything into the queso namespace/scoping. 

Passes makecheck on my box. Addition of a single test, 'test_exception' in tests provides very rudimentary coverage of some of this capability.