Threadpoolize all the things

These are all the remaining function from the list in #338 (closed). I've tested this as far as possible on my laptop, i.e. MPI and gravity should work.

Once this, threadpool_task_plots2 and engine_barrier are merged, it would probably be a good idea to have another look at the threadpool task plots for EAGLE_25.

I'll work on this one once the other merge requests have been processed.

Added 116 commits:

• 16194ad7...ddad736c - 109 commits from branch master
• 516551d8 - use a threadpool_map for engine_make_hydro_tasks.
• b2982133 - convert engine_make_self_gravity_tasks to use a threadpool_map. still have to cr…
• d255638f - convert engine_count_and_link_tasks to a threadpool mapper function.
• f9f3cf96 - add cell_set_super_mapper.
• 9592743a - wrap engine_make_hierarchical_tasks in a threadpool mapper function.
• 885a733f - convert engine_make_extra_hydroloop_tasks to a threadpool mapper function.
• 52825df8 - Merge branch 'threadpoolize_all_the_things' of gitlab.cosma.dur.ac.uk:swift/swif…

All of my tests passed with this branch. I'll accept it unless someone shouts.

Cool! @pdraper, can you re-run the threadpool mapper plot script with this change in to see what the big white gaps look like now? Thanks!

With this merged in I was going to:

• Up the version number to 0.6.0 as it is becoming untracktable and we have done a lot of scaling improvements since 0.5.0
• Run the usual scaling test
• Make task and threadpool plots on 16 cores.

OK, will set the EAGLE_25 check away.

Added 1 commit:

• 7dd3495a - Pointer arithmetic fix for icc warning. Documentation fixes.

Status changed to merged

mentioned in commit 6dff7c9e

mentioned in issue #338 (closed)

Here are some new threadpool plots:

• http://astro.dur.ac.uk/~pdraper/swift/threadpool-plots/eagle_25_9-1/threadpool-index.html

If you search hard you'll find the now more colourful many tasked steps...

tl;dr: http://astro.dur.ac.uk/~pdraper/swift/threadpool-plots/eagle_25_9-1/poolstep333r.html

Does exactly what it was intended to do! Excellent.

Sweet! So do we know what the two remaining white gaps are?

Also, the super-cell fix I have in mind should reduce the fraying in the smaller steps...