removed unnecessary functions, added comments, added READMEs to examples

examples/CoolingBox/README

examples/CoolingBox/analytical_test.py

examples/CoolingBox/coolingBox_non-cosmo.yml

examples/CoolingBox/makeIC.py

examples/CoolingRates/README

examples/CoolingRates/cooling_rates_plot.py

examples/CoolingRates/testCooling.c

examples/CoolingRates/testCooling.yml

examples/CoolingRates/test_script.sh

examples/CoolingTest_Alexei/Makefile.am

examples/CoolingTest_Alexei/plots.py

examples/CoolingTest_Alexei/plots_nh.py

examples/CoolingTest_Alexei/testCooling.c

examples/CoolingTest_Alexei/testCooling.yml

examples/CoolingTest_Alexei/testCooling_messy.c

examples/CoolingTest_Alexei/testCooling_script.c

examples/EAGLE_12/run.sh

src/Makefile.am

src/cooling/EAGLE/cooling.c

src/cooling/EAGLE/cooling.h