- construct/assign from Zero

- add boundBox::directionBit enum which contains the same values as the
  treeBoundBox::octantBit enum, but without the attached meaning

- These are not defined in the C++ standard for cmath, so allow for
  compilation without them. Will need to provide replacements in the
  future or rework.

- new regExpCxx wrapper for C++11 regex support with drop-in
  compatibility with existing code.

- regExpPosix (was regExp), for future phase out in favour of regExpCxx.

- The regExp header will continue to be used for defining an
  appropriate typedef corresponding to the preferred implementation.

- this information is more related to processor, not OS

- relocates some logic from makefiles/general into platform-specific
  overrides

- for more clarity, make read/write of rpm and mean-diameter contingent
  on nonDimensional == true

- write finiteArea meshes and fields to standard surface output
  formats (Ensight, VTK, etc).

- less used bookkeeping/convenience methods that may be phased out
  in the future

- instead of deciding beforehand if a surface format requires a separate
  geometry file (or if a geometry file should be written if no fields were
  written) now determine afterwards if something was written.

  This improves the overall reliability (consistency) and is more
  convenient for the caller as well.

- PtrDynList support for move append list:
  can be used to concatenate pointer lists into a single one

- include resize in PtrDynList squeezeNull as being a natural
  combination

- support sorting operations for pointer lists (PtrListOps)

- comparison operator, for sorting based on the position of the origin.

- allow modification of the origin.

- zero-initialise for null constructor: base components are vectors
  and cheap to initialise.

- 'unfriend' the output operator: it uses public access methods

- considered an error by the PGI compiler

- remove writeGeometry() in favour of write() and make it pure virtual
  so that all writers must explicitly deal with it.

- establish proxy extension at construction time and treated as an
  invariant thereafter. This avoids potentially surprising changes in
  behaviour when writing.