Related to #37

Moved Simulation::init() to Constructor, Simulation:free() to destructor and exchanged some members of Simulation with unique_ptr instances.

- Parameter is passed as reference now (according to https://isocpp.github.io/CppCoreGuidelines/CppCoreGuidelines#f7-for-general-use-take-t-or-t-arguments-rather-than-smart-pointers)
- Where possible LBMSimulationParameter is passed instead of Parameter

Added SG model to StressBC, added Timer-class which wraps existing timer in Simulation, added round-off correction in TurbulentViscosityCumulantK17CompChim_Device (testing ongoing)

In copyEdgeNodes the nodes were copied to the wrong places of the send vector. The problem was that the full vector sendProcessNeighborHostAllNodes was used for copying instead of the shorter vector sendProcessNeighborHostAfterFtoC