Handling Sensitive Answer Tests
Many tests are currently very sensitive to compilers/optimizations. An incomplete list of these failing tests include: AdiabaticExpansion, CollideTest, ProtostellarCollapse_Std, PhotonTestAMR
We should figure out a way to handle different sensitivities. Perhaps a flag during testing such as: --rtol=1.0e-7, much like what is used in the nose testing framework.