Better naming convention for VELOCIraptor-related i/o parameters. Use the correct value for the time of first output in engine_compute_next_stf_time()

Add timestep (time between two scale-factors) to hydro prepare force.

See merge request !609

Better documentation of the functions in timeline.h. Corrected get_min_active_bin() to report the correct minimal bin on the 1st step.

Better documentation of the intrinsics we employ. Also declare them as const-functions to help the compiler.

Prevent VELOCIraptor from running for ever in a loop at the 0th time-step when asking for an output every N steps.

Add a small cosmological volume example with gas and a script to plot the temperature evolution of the Universe.

Add a small cosmological volume example with gas and a script to plot the temperature evolution of the Universe.

Use the primoridal Helium abundance to compute the Hydrogen mass fraction. Optionally read the temperature transition from the YAML parameter file.

Use the threaded version of FFTW to speed-up the PM part of the code.

See merge request !608

Add option to label snapshots by the time

See merge request !601

Can be uninitialized when task is MPI

Add ParMETIS support

See merge request !506

Conflicts:
	src/partition.c

Prevent users from generating gas from the ICs if they are running without the hydrodynamics policy.

Parallel mesh assignment and simplification of M2L kernel

See merge request !604

Correct debugging check for the size of the collected time-step. A step of size 0 is acceptable on the last step.

Only collect time-steps for hydro and gravity for the cells that have related…

Closes #455

See merge request !605