- this is consistent with compiler defaults, and helps Darwin users

- resolve in favour of "inline explicit", which had marginally more
  uses and provides consistent prefixing for inline methods.

- make the purpose more explicit, and reduces some work for the
  compiler as well.

- improves backward compatibility and more naming consistency.
  Retain setMany(iter1, iter2) to avoid ambiguity with the
  PackedList::set(index, value) method.

- required for std::iterator_traits specialization, which is used by
  the std::max_element algorithm on Darwin.

- consistency with make and more succinct.

- reduce code duplication in findEtcFiles.

Basic directional refinement:
- only for coordinate aligned meshes
- only for refinementRegions
See the mesh/snappyHexMesh/aerofoilNACA0012_directionalRefinement
tutorial.

Haakan Nilsson authored May 17, 2018 and Mark Olesen committed May 17, 2018

- the current working path with replacements for base-level
  OpenFOAM env variables such as FOAM_RUN, WM_PROJECT_DIR,
  WM_PROJECT_USER_DIR etc

  Can be used directly from the command-line or embedded into a
  command prompt. For example,

      PS1='$(foamPwd)\n\u\$ '

- aliases for user solver/utilities located under "$WM_PROJECT_USER_DIR":
  (ufoam, uapp, usol, uutil)

- disallow insert() of raw pointers, since a failed insertion
  (ie, entry already existed) results in an unmanaged pointer.

  Either insert using an autoPtr, or set() with raw pointers or autoPtr.

- IOobjectList::add() now takes an autoPtr instead of an object reference

- IOobjectList::remove() now returns an autoPtr instead of a raw pointer

- use refCount instead of the tmp<...>::refCount alias

- tie the MPI rules to the base compiler type *without* its version.
  Eg, linux64Gcc (which exists) instead of linux64Gcc81