Make use of a temporary threadpool in the reading routines to speed-up the duplication of parts into gparts.

Added support for more Kaby-Lake CPUs. Also added better defaulting options for older GCCs to cope with this unknow architecture.

Correctly compute the separate time-bins for hydro and gravity at the bottom of the tree in space_split_recursive()

In the gravity FFT task only verufy if the multipoles are drifted when the debugging checks are activated.

Print more information about multipoles and cells when an undrifted multipole is encountered in the MM task.

Set the nodeID for the engine and the cells to be the same.

See merge request !476

Dopair vec mpi

See merge request !456

Make the hydro schemes compute the dirfted velocities themselves when collecting statistics.

See merge request !474

Removed the now obsolete checks that all correct tasks are active. Will need to be re-done correctly.

Add a SWIFT_DEVELOP_MODE flag to enable development code options

Closes #391

See merge request !473

Just uses abort() instead of exit() in non-MPI code

Compress hdf5 files and perform same tests with MPI.

See merge request !468

Kick1 update

See merge request !472

In kick1 after all is done, update the part's acceleration to include the gpart acceleration. This allows the hydro drift to use the correct accelerations for hydro predictions.