Integration adjoint

See merge request OpenFOAM-plus!269

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

- now only needed when specify compiling -m32 on a 64-bit system.

  Internally use the __SIZEOF_LONG__ compiler macro (gcc, icc, llvm)
  to define when long is actually an int32_t.

- pending resolution of cyclic dependencies

- a leftover from much older VTK versions that had poor handling of
  the scalar bar text.

- also enables smooth restart for solitary waves

TUT: pimpleFoam/channelDFSEM395 - added example use of Lamb vector

See merge request OpenFOAM-plus!267

- relocated BuildIssues.txt -> doc/BuildIssues.md

- adjust copyright dates for manpages

- enable by default on Windows, disable by default on non-Windows.

ENH: functionObject: refactored co-ordinate system usage and new forceCoeffs members

See merge request OpenFOAM-plus!246