Also make sure ParMETIS is mentioned as well as METIS

This should give memory balance like the initial partition, probably more useful to maintain this

Delayed foreign allocation

Closes #456

See merge request !716

Better link size estimates

Closes #521

See merge request !712

Do not count the particles in the leaves when looking for the number of foreign particles to allocate.

New ghost iteration scheme

See merge request !714

Updates to the Velociraptor interface for Pascal's runs

See merge request !717

Only write the cooling information to snapshots if we are running with the cooling or temperature policy.

Correclty move the pointer at the top-level when moving from proxy to proxy. Simplify the linking recursion.

Count the number of particles in foregin cells that have tasks only. Allocated memory based on that counter. Link the cells recursively based on that counter.