Implement more general conversion functions for i/o. Can now add one that does box-wrapping  of particles.

Use the equation of state functions in a few more places in the gizmo code to be more robust to changes.

Intel compiler does not like bit-comparison on enumerated types. Use an integer for the step properties instead.

Support for OSX

Closes #364

See merge request !442

Add information to stdout and timestep.txt about what happened in the step

See merge request !455

Make loop bounds consistent.

See merge request !452

Add information to stdout and timestep.txt about what happened in the step (rebuild, repartition, snapshot, ...)

Large hdf5 reads

See merge request !453

When compiling with the iosthermal equation of state, read the constant thermal energy from the YAML file.

Resolve "Check for drifted state in vectorized tasks"

Closes #380

See merge request !449