Changed ModelEvalTemp to evaluate model given composite temperature (fuel/coolant).
Changed this and ModelEvalPower to apply same damping factor to both temperatures.
Not sure what changes made to other files.
Fixed the issue causing the mpi issue if ModelEvalFluidTemp, added
overloaded call to ComputeSpecificHeat to evaluate at a single temp
instead of a vector of temps, and modified some pass/failure issues
in the tests
Modification to the flow model discretization.