Merge branch 'io_selection_changes' into 'master'

doc/RTD/source/ParameterFiles/output_selection.rst

examples/SmallCosmoVolume/SmallCosmoVolume_Snipshots/README

...ples/SmallCosmoVolume/SmallCosmoVolume_Snipshots/getIC.sh

...allCosmoVolume/SmallCosmoVolume_Snipshots/output_list.txt

...smoVolume/SmallCosmoVolume_Snipshots/plotTempEvolution.py

examples/SmallCosmoVolume/SmallCosmoVolume_Snipshots/run.sh

...lCosmoVolume/SmallCosmoVolume_Snipshots/select_output.yml

...oVolume/SmallCosmoVolume_Snipshots/small_cosmo_volume.yml

examples/main.c

examples/main_fof.c

examples/parameter_example.yml

src/Makefile.am

src/common_io.c

src/common_io.h

src/distributed_io.c

src/engine.c

src/engine.h

src/output_list.c

src/output_list.h

src/output_options.c