- can be used for outputing sampled surfaces in x3d format for direct
  import in other rendering tools.

Reacting heterogeneous cloud

See merge request OpenFOAM-plus!242

All remote contributions to interpolation stencils now
get added as 'processor' type lduInterfaces. This guarantees
a consistent matrix, e.g. initial residual is normalised to 1.

Second change is the normalisation of the interpolation discretisation
which uses the diagonal from the unmodified equation. This helps
GAMG.

- this corresponds more closely to the expected behaviour of a
  patch-average value being independent of the local face
  discretization

Feature reflective solar load

See merge request OpenFOAM-plus!243

- localize some functionality, std::array for digest internals.
  Additional append sub-string methods, pass-through write of digest
  etc.

- only apply component-wise transformCoupleField for non-scalar types

- amalgamate dlSym() and dlSymFound() into a single dlSymFind() backend
  with optional 'required' argument. This makes it possible to
  query and assign at once.

- previously would have different SHA1 depending on whether the
  string was a C-string, a C++-string or if the SHA1 was calculated
  directly or via the OSHA1stream.

    - SHA1("string")
    - OSHA1stream << "string";
    - OSHA1stream << string("string");

  By avoiding string quoting on output, they now all deliver the same
  result. This also means that the following will no longer change the SHA1
  content, since it does not add anything:

    osha<< string() << string() << string() << string();

  This would have previously add a pair of double quotes each time!

- failed when nAlphaSubCycles > 1 and nOuterCorrectors > 1.
  Fixed thanks to Henning Scheufler (DLR Bremen).

- Eg, with surface writers now in surfMesh, there are fewer libraries
  depending on conversion and sampling.

COMP: regularize linkage ordering and avoid some implicit linkage (#1238)

- avoids unnecessary cyclic dependency

- change internal naming from 'EXE_EXT' to 'EXT_EXE' for symmetry with
  'EXT_SO'

- continuation of commit 0e7954c2

ENH: downgrade abort() to exit() in some places (#1238)

Feature indirect lists

See merge request OpenFOAM-plus!253

See merge request OpenFOAM-plus!254

- now also track if the cellSet or cellZone has changed on point
  motion.

- also available as equal() member function

- make I/O operators global (non-member)

Patch contributed by Gavin Ridley.