Use getticks() to get enough randomness when enqueing tasks without owners.

How about this version ?

See merge request !411

Added cpuid for Kaby Lake processor and corresponding compilation flags.

Could you let me know whether this works ? I think I got the correct cpuid pattern for KabyLake...

See merge request !410

When padding the gravity cache, use -2 * cell->width for the particle position to make sure this is an invalid (but reasonable) position.

Make the expected number of tasks per cell a parameter.

Previously we had a max of 96, much smaller numbers will work depending on the job

See merge request !395

Replace calls to rand() by calls to rand_r() in the scheduler

Implements #302 using @d74ksy's changes. 

See merge request !405

More specialised timers for the gravity leaf-leaf interactions. Improvements to the vectorization of the PM leaf-leaf interaction.

Split the P2P and M2P into two separate (vectorizable) loops in the leaf-leaf gravity P-P interactions.

Cache auto vec

Auto-vectorise populating the cache with hints to the compiler and `restrict` keyword.

See merge request !404