Merge with master + fix conflict

configure.ac

doc/RTD/source/HydroSchemes/index.rst

doc/RTD/source/HydroSchemes/shadowswift.rst

doc/RTD/source/NewOption/index.rst

doc/RTD/source/NewOption/sink_adding_new_scheme.rst

doc/RTD/source/ParameterFiles/parameter_description.rst

doc/RTD/source/Snapshots/index.rst

doc/RTD/source/SubgridModels/GEAR/sinks/introduction.rst

doc/RTD/source/SubgridModels/GEAR/sinks/params.rst

doc/RTD/source/SubgridModels/GEAR/sinks/sink_imf.png

doc/RTD/source/SubgridModels/GEAR/sinks/sink_scheme.png

doc/RTD/source/SubgridModels/GEAR/sinks/theory.rst

...IsolatedGalaxy/IsolatedGalaxy_multi_component/GEAR/README

...atedGalaxy/IsolatedGalaxy_multi_component/GEAR/params.yml

...tedGalaxy/IsolatedGalaxy_multi_component/GEAR/run_sink.sh

...IsolatedGalaxy/IsolatedGalaxy_multi_component/makeDisk.py

...rTests/AdvectionDifferentTimeStepSizes_1D/plotSolution.py

examples/RadiativeTransferTests/Advection_1D/README

examples/RadiativeTransferTests/Advection_1D/plotSolution.py

...es/RadiativeTransferTests/Advection_1D/rt_advection1D.yml