- silence clang warnings

- this is somewhat like labelRange, but with a stride.
  Can be used to define slices (of lists, fields, ..) or as a range specifier
  for a for-loop. For example,

      for (label i : sliceRange(0, 10, 3))
      {
          ...
      }

- removed unused decrement() and increment() methods, which provided
  identical functionality as the ++, +=, --, -= operators.

Adding pMin,Pmax pressure control to buoyantPimple and
chtMultiReagion

- with the wmake rules we may have some compiler options bound to the
  internal compiler variable. For example,

     CC  = g++ -std=c++11 -m64

     c++FLAGS = ...

  So shift any flags from CC to CXXFLAGS for the output of
  'wmake -show-cxx', 'wmake -show-cxxflags', etc.

  This makes it much easier to handle the values correctly elsewhere.
  Eg,

      CXX="$(wmake -show-cxx)" CXXFLAGS="$(wmake -show-cxxflags)" \
         ./configure

- provide dedicated detection 'have_ptscotch' function that can be
  used after the 'have_scotch' function.

  It sets the PTSCOTCH_ARCH_PATH, PTSCOTCH_INC_DIR, PTSCOTCH_LIB_DIR
  and helps when the serial and parallel versions are located with
  different logic.

- the writer nFields() is a separate type of accounting (currently
  only needed by VTK legacy) and is independent of the geometry.

oversetInterpolationSuppressed dict.

- file-local static for saving the old action, which moves system
  dependencies out of the header files.

- set/reset of signals as file-local functions

STYLE: use csignal header instead of signal.h

- this improves overall consistency and is independent of higher level
  tagging as ASCII or BINARY for IFstream, OFstream etc.

- this adds support for various STL operations including

    * sorting, filling, find min/max element etc.
    * for-range iteration

STYLE: use constexpr for VectorSpace rank

- consistent with use of <cstdlib> and makes for a stronger distinct
  from Foam::abort etc.

- this improves overall consistency and makes re-reading as a generic
  patch field behave properly when the underlying patch has zero size.

- use git show/diff -w when viewing

- add an additional test for wmake pre-processing

- similar to the global '/' operator, but taking raw strings and not
  performing any stripping.

  Was previously a local function within POSIX.C, but it is useful enough
  to be in fileName itself.

- having whitespace in fileName can be somewhat fragile since it means
  that the fileName components do not necessarily correspond to a
  'Foam::word'. But in many cases it will work provided that spaces
  are not present in the final portion of the simulation directory
  itself.

    InfoSwitches
    {
        // Allow space character in fileName (use with caution)
        allowSpaceInFileName    0;
    }

- now use doClean=true as default for fileName::validate(). Was false.

  Unlike fileName::clean() this requires no internal string rewrite
  since the characters are being copied.  Also handle any path
  separator transformations (ie, backslash => forward slash) at the
  same time. This makes it resemble the std::filesystem a bit more.

- can be useful for retrieving the compilation flags for use with other
  make systems (eg, cmake)

  * wmake -show-compile   (C++ not C)
  * wmake -show-cxx
  * wmake -show-cxxflags

- operators are still incomplete, as are dimensioned fields,
  field-fields etc.

- split complexFields into separate complexField, complexVectorField files

- add construction from and conversion to std::complex, which allows
  easier wrapping of functions

- add Foam:: functions for complex versions of sin, cos, ...

- grid(i,j,k) method for returning the grid point at an i-j-k location