- to simplify/unify error handling

STYLE: use NotImplemented instead of longer notImplemented(...)

- unfriend HashSet, HashTable IO operators

- global min(), max(), minMax() functions taking a labelHashSet and an
  optional limit. For example,

      labelHashSet set = ...;

      Info<< "min is " << min(set) << nl;
      Info<< "max (non-negative) " << max(set, 0) << nl;

- make HashTable iterator '->' dereferencing more consistent by also
  supporting non-pointer types as well.

- read HashTable values in-situ to avoid copying

- add triSurface::subsetMesh single-parameter variant

- reduced clutter. Mostly only need to scan source tree.

- 00-dummy: use wmake/src/Allmake to get native (not cross-compiled)
  wmake toolchain binaries

A set of libraries and executables creating a workflow for performing
gradient-based optimisation loops. The main executable (adjointOptimisationFoam)
solves the flow (primal) equations, followed by the adjoint equations and,
eventually, the computation of sensitivity derivatives.

Current functionality supports the solution of the adjoint equations for
incompressible turbulent flows, including the adjoint to the Spalart-Allmaras
turbulence model and the adjoint to the nutUSpaldingWallFunction, [1], [2].

Sensitivity derivatives are computed with respect to the normal displacement of
boundary wall nodes/faces (the so-called sensitivity maps) following the
Enhanced Surface Integrals (E-SI) formulation, [3].

The software was developed by PCOpt/NTUA and FOSS GP, with contributions from

Dr. Evangelos Papoutsis-Kiachagias,
Konstantinos Gkaragounis,
Professor Kyriakos Giannakoglou,
Andy Heather

and contributions in earlier version from

Dr. Ioannis Kavvadias,
Dr. Alexandros Zymaris,
Dr. Dimitrios Papadimitriou

[1] A.S. Zymaris, D.I. Papadimitriou, K.C. Giannakoglou, and C. Othmer.
Continuous adjoint approach to the Spalart-Allmaras turbulence model for
incompressible flows. Computers & Fluids, 38(8):1528–1538, 2009.

[2] E.M. Papoutsis-Kiachagias and K.C. Giannakoglou. Continuous adjoint methods
for turbulent flows, applied to shape and topology optimization: Industrial
applications. 23(2):255–299, 2016.

[3] I.S. Kavvadias, E.M. Papoutsis-Kiachagias, and K.C. Giannakoglou. On the
proper treatment of grid sensitivities in continuous adjoint methods for shape
optimization. Journal of Computational Physics, 301:1–18, 2015.

Integration into the official OpenFOAM release by OpenCFD

- pending resolution of cyclic dependencies

- do not write 0/ directory
- clean case in ./Allclean

Adding poly solid thermo to InterfaceCompositionModel for use
on icoReactingMultiphaseInterFoam

Integration of VOF MULES new interfaces. Update of VOF solvers and all instances
of MULES in the code.
Integration of reactingTwoPhaseEuler and reactingMultiphaseEuler solvers and sub-models
Updating reactingEuler tutorials accordingly (most of them tested)

New eRefConst thermo used in tutorials. Some modifications at thermo specie level
affecting mostly eThermo. hThermo mostly unaffected

New chtMultiRegionTwoPhaseEulerFoam solver for quenching and tutorial.

Phases sub-models for reactingTwoPhaseEuler and reactingMultiphaseEuler were moved
to src/phaseSystemModels/reactingEulerFoam in order to be used by BC for
chtMultiRegionTwoPhaseEulerFoam.

Update of interCondensatingEvaporatingFoam solver.

ENH: define addition/subtraction operations for scalar and complex

- required since construct complex from scalar is explicit
- additional tests in Test-complex

- forces c++DBUG='-DFULLDEBUG -g -O0' for the compilation, to allow
  localized debugging during development without file editing and
  while retaining the WM_COMPILE_OPTION (eg, Opt)

  Note that switching between 'wmake' and 'wmake -debug' will not
  cause existing targets to be rebuilt. As before, these are driven by
  the dependencies. An intermediate wclean may thus be required.

- error trapped by C++11 regex

- generalize identity matrix constructors for non-scalar types

- add constructors using labelPair for the row/column sizing information.
  For a SquareMatrix, this provides an unambiguous parameter resolution.

- reuse assignment operators

STYLE: adjust matrix comments

- additional operators:
  + compound assignment
  + inner product: operator&
  + outer product: operator^

- additional functions:
   - MatrixBlock methods: subColumn, subRow, subMatrix
   - L2 norms for matrix or column
   - trace, diag, round, transpose

- MatrixBlock methods: col(), block() are deprecated since their
  access patterns with (size, offset) are unnatural/unwieldy.

- verifications by test/Matrix/Test-Matrix

- simplify faceZone selection in surfaceMeshExtract

- adjust naming of quaternion 'rotationSequence' to be 'eulerOrder'
  to reflect its purpose.

- provide rotation matrices directly for these rotation orders in
  coordinateRotations::euler for case in which the rotation tensor
  is required but not a quaternion.

Modified revert of commit 6c6f777b.

- The "alphaContactAngleFvPatchScalarField" occurs in several
  places in the code base:

    - as abstract class for two-phase properties
    - in various multiphase solvers

  To resolve potential linking conflicts, renamed the abstract class
  as "alphaContactAngleTwoPhaseFvPatchScalarField" instead.

  This permits potential linking of two-phase and multi-phase
  libraries without symbol conflicts and has no effect on concrete
  uses of two-phase alphaContactAngle boudary conditions.

- support move insert/set and emplace insertion.

  These adjustments can be used for improved memory efficiency, and
  allow hash tables of non-copyable objects (eg, std::unique_ptr).

- extend special HashTable output treatment to include pointer-like
  objects such as autoPtr and unique_ptr.

ENH: HashTable::at() method with checking. Fatal if entry does not exist.

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