Update single node task plots

Update the non-MPI task plot scripts to offer same speed ups as the MPI versions.

See merge request !83

Fix MPI tag collision Issue #68

Increased the maximum cell tag to 2^29 to prevent the MPI tag collision issue #68.

See merge request !82

PASC paper



See merge request !80

Corrected the Wendland C2 kernel.

Still needs checking. @jwillis, can you check whether the number of neighbours is sensible with this version ?

The definition of kernels is still not completely optimal so minor changes may appear at a later stage in the project when nothing more urgent needs attention.

See merge request !77

NUMA-aware affinity

Resolves #76. Yes, ```hyperthreads_present``` is bonkers - it's easy to detect whether the processor supports the technology, but this is the best I've found to tell whether it's enabled.

See merge request !78

* Alternative: does .../thread_siblings contain more than a single 1?
  n.b. May or may not contain a comma if so.

* This is not vectorisation-specific.
* There may be better trade-offs between HT and NUMA.
* Maybe print a warning when we require multiple NUMA nodes.
* Must also detect when Hyper-Threading is not present.
* Probably better as a configure flag, rather than conditional only upon
  the availability of libnuma.
* ~15-40% performance improvement on COSMA.