Added scripts for generating plots for chapters 7 and 8 in the thesis (#526)

pySDC/implementations/problem_classes/GrayScott_MPIFFT.py

...plementations/problem_classes/generic_MPIFFT_Laplacian.py

pySDC/projects/GPU/README.rst

pySDC/projects/GPU/analysis_scripts/3d_plot_GS_large.py

pySDC/projects/GPU/analysis_scripts/large_simulations.py

pySDC/projects/GPU/analysis_scripts/parallel_scaling.py

pySDC/projects/GPU/analysis_scripts/plot_RBC_matrix.py

...C/projects/GPU/analysis_scripts/plot_large_simulations.py

pySDC/projects/GPU/configs/GS_configs.py

pySDC/projects/GPU/configs/RBC_configs.py

pySDC/projects/GPU/configs/base_config.py

pySDC/projects/GPU/paper_plots.py

pySDC/projects/GPU/run_experiment.py