Update plotSolutions of star formation example and remove the two other examples

examples/IsolatedGalaxy_starformation/plotSolution.py

examples/IsolatedGalaxy_starformation_25p/KS_law.py

.../IsolatedGalaxy_starformation_25p/StarFormationHistory.py

examples/IsolatedGalaxy_starformation_25p/gasdensity.py

examples/IsolatedGalaxy_starformation_25p/getIC.sh

...ples/IsolatedGalaxy_starformation_25p/isolated_galaxy.yml

examples/IsolatedGalaxy_starformation_25p/run.sh

...olatedGalaxy_starformation_25p_intermediate/gasdensity.py

...es/IsolatedGalaxy_starformation_25p_intermediate/getIC.sh

...Galaxy_starformation_25p_intermediate/isolated_galaxy.yml

...ples/IsolatedGalaxy_starformation_25p_intermediate/run.sh