Parameter Sensitivity Support

[vikramvgarg]

Forward/Adjoint Sensitivity <-- ParameterVector(Parameter Objects) <-- ParameterHandler(PhysicalConstantAccessors) <-- Physics Classes

From the user side: The GRINS input file will have a sensitivity analysis section where they will specify the parameters to which the QoI senstivities are to be computed, these will be strings in the GetPot canonical form. So for eg, viscosity 'mu' will be specified as "Physics/Materials/Viscosity/mu".

In GRINS: The ParameterHandler will ask the instantiated Physics classes if they have parameters that the user has asked sensitivities for, and obtain pointers to the same from the classes.

In libMesh: ParameterVector will be refactored to hold Parameter Objects (smart pointers) rather than simply pointers to Numbers. These objects will own functions that perturb/scale the parameters.