1) The sign of radiative flux (qr) for modes Power and HeatFlux was
corrected.

2) Relaxation factor implementation was incomplete. Now caching
valueFraction and refValue from  the previous time step.

- use Clang instead of Gcc for Darwin since this is its system
  compiler. The user can force use of Gcc by using Gcc92 etc.

- make etc/cshrc sed check more robust.

- replace tcsh (${%var}) syntax with ("${var}" != "")

[Fixes and ideas from Alexey Matveichev]

CONFIG: do not source the gperftools environment by default

- this is now an used feature, but can be re-enabled by advanced users
  if required.

- add edit of llvm/mesa/vtk paths. Reduce some verbosity

- include Darwin in foamInstallationTest, foamSystemCheck to avoid
  a false negative.

- as a side-effect of recent changes, command-line stripping of .gz
  extensions on input was lost. For example,

      OK:    surfaceTransformPoints file.stl ...
      Fail:  surfaceTransformPoints file.stl.gz ...

- restore the previous behaviour of silently stripping the '.gz'
  extension on input.

ENH: add triSurface::New selector entry point

- for symmetry with MeshedSurface

  Now the thermal baffle can be extrapolated from a patch which is
  coupled to the bottom patch of the solid region.

  The user can set the T bc on the 'top' patch of the solid.

  The new keyword is 'internal' and its default is true. Check new
  tutorial for an example:

  tutorials/heatTransfer/buoyantSimpleFoam/roomWithThickCeiling/

- can aid when creating source-only or binary-only packages

- reads/write shell elements
  Output elements are "bunched" according to type and their set
  without reordering.

- preliminary reading of solids without extraction.
  Handling of *Surface specifications is not implemented

- enhancement and potential breaking change.

  Nastran surface writer previously used the keyword 'scale' for
  field scaling, which was applied uniformly to all output fields.

  Change the meaning of 'scale' to be geometric scaling
  (consistent with reading triSurfaceMesh etc).

  New 'fieldScale' entry is an optional dictionary of scaling
  parameters.

  Example,

      nastran
      {
          scale   1000;     // [m] -> [mm]
          fieldScale
          {
             "p.*"   0.01;  // [Pa] -> [mbar]
          }
      }

- adjustments to internal handling to improve run-time addition of
  other formats (eg, with additional user library)

  For example, to write a binary STL with a '.stl' extension:

    $ surfaceMeshConvert input.obj  -write-format stlb  output.stl

  Or in a sampler,
  to specify the input type without ambiguity:

  surf
  {
      type        meshedSurface;
      surface     sampling.inp;

      fileType    starcd;
      scale       0.001;
      ...
  }

STYLE: regularize naming for input/output scaling

  * -read-scale   (compat: -scaleIn)
  * -write-scale  (compat: -scaleOut)

CONFIG: change edge/surface selection name for STARCD format

- now select as "starcd" instead of "inp" to avoid naming ambiguity
  with abaqus

- eg, for a uniform field and auto range.

- had a PrimitivePatch with SubField, but now use const pointField&.

  There is no derivation path from a pointIOField to SubField<point>,
  so a const reference makes more sense.

- face_type, point_type (similar to STL value_type, etc).
  The naming avoids potential confusion with template parameters.

- rename private typedef from ParentType to MeshReference for more
  consistency with polySurface etc.

- regression introduced by 431c9632

  The triSurface dictionary constructor applies the scaling,
  and thus it can be reported, but not applied in triSurfaceMesh

- refactor common exit/abort code

- support single-parameter output. Eg,

    FatalError("some-executable")
        << "Cannot load something\n"
        << exit(FatalError);

- previously used a Pstream::exit() invoked from the argList
  destructor to handle all MPI shutdown, but this has the unfortunate
  side-effect of using a fixed return value for the program exit.

  Instead use the Pstream::shutdown() method in the destructor and allow
  the normal program exit codes as usual. This means that the
  following code now works as expected.

  ```
  argList args(...);

  if (...)
  {
      InfoErr<< "some error\n";
      return 1;
  }
  ```

- orphaned file: extendedFeatureEdgeMeshI.H

- unused primitiveFaceZone typedef.
  Identical to indirectPrimitivePatch typedef

- conversion, sampling, surfMesh

STYLE: double-quote "$@" for isTest/notTest

- placed in stdFoam.H (as well as autoPtr.H) for general availability

STYLE: minor adjustments to autoPtr code layout

- preferentially handle Allwmake.override, which allows packaging
  tools to define alternative make scripts, or selectively disable
  components.

- remove legacy handling of 'Optional' directory.
  Conditionals have since migrated into scripts themselves and/or
  use the wmake/scripts/have_* framework.

BUG: missed passing -debug for Allwmake scripts

- makes it easier to run/clean individual cases