Fixes and documentation of a few more places where the implementation will need to be updated in the future.

Also tag all top-level cells with foreign partners, do the multipole exchange after maketasks so that we have all the necessary tags available

Add some additional checks as well

Add some implicit tasks to walk the tree up and down after the multipole initialisation and before the downpass.

Matthieu Schaller authored May 23, 2018 and Matthieu Schaller committed Jun 18, 2018

Extract the mesh gravity forces to a separate set of functions. Get the forces directly from the mesh to the gparts. Do not use the tree here.

rolled back the changes to space_split_mapper as the old version was faster, but kept the part-gpart relinking changes.

first step in breaking stuff, modify cell_split so that it only splits the buffers, not the actual particle data.

This reverts commit 35896dad.

Re-introduce the 'end_force' function as a task in order for the cooling function to be called at the right place in the time-step.