use stack api in examples

Wrap/Python/src/bornagain/std_samples.py

auto/Examples/bayesian/likelihood_sampling.py

auto/Examples/fit/specular/Specular1Par.py

auto/Examples/specular/AlternatingLayers1.py

auto/Examples/specular/SpecularSimulationWithRoughness.py

auto/Examples/varia/MaterialProfile.py

auto/FigExamples/bayesian/likelihood_sampling.py

auto/FigExamples/fit/specular/Specular1Par.py

auto/FigExamples/specular/AlternatingLayers1.py

auto/FigExamples/specular/SpecularSimulationWithRoughness.py

auto/FigExamples/varia/MaterialProfile.py

auto/MiniExamples/bayesian/likelihood_sampling.py

auto/MiniExamples/fit/specular/Specular1Par.py

auto/MiniExamples/specular/AlternatingLayers1.py

.../MiniExamples/specular/SpecularSimulationWithRoughness.py

auto/MiniExamples/varia/MaterialProfile.py

rawEx/bayesian/likelihood_sampling.py

rawEx/fit/specular/Specular1Par.py

rawEx/specular/AlternatingLayers1.py

rawEx/specular/SpecularSimulationWithRoughness.py