Work on pdd and some other small code refactorings.

AMDiS/src/AMDiS_fwd.h

AMDiS/src/DOFMatrix.cc

AMDiS/src/ParallelDomainProblem.cc

AMDiS/src/Recovery.h

AMDiS/src/RecoveryEstimator.h

AMDiS/src/RefinementManager.h

AMDiS/src/RefinementManager1d.h

AMDiS/src/RefinementManager3d.h

AMDiS/src/ResidualEstimator.h

AMDiS/src/ResidualParallelEstimator.h

AMDiS/src/RobinBC.h

AMDiS/src/SMIAdapter.h

AMDiS/src/ScalableQuadrature.h

AMDiS/src/SecondOrderAssembler.h

AMDiS/src/Serializable.h

AMDiS/src/Serializer.h

AMDiS/src/SolutionDataStorage.h

AMDiS/src/SolverMatrix.h

AMDiS/src/StandardProblemIteration.h

AMDiS/src/SubAssembler.h