- adjust known gcc/clang compiler versions

For example,

   $ someSolver -info-switch writeOptionalEntries

- note that values changed via the command-line are changed after the
  etc/controlDict entries, but *before* any case-local
  system/controlDict entries.

  However, in many testing cases the command-line options eliminate
  the need for such local file modifications.

ENH: cleanup handling of local debug switches in Time

- add as methods directly on simpleObjectRegistry to avoid code
  duplication

STYLE: adjust internal naming of ITstream parameters

- now reports the dictionary, entry, default. For example,

  Dictionary: <case>/0/nut.boundaryField.wall Entry: Cmu Default: 0.09
  Dictionary: <case>/0/nut.boundaryField.wall Entry: kappa Default: 0.41
  Dictionary: <case>/0/nut.boundaryField.wall Entry: E Default: 9.8

- suppress reporting for debug, optimisation switches since this
  generates extremely noisy output

- cannot rely on the entries having a keyword method

STYLE: apply consistent hash table sizing for debug objects

It was tracking to find the wanted sampling location. This tracking
was using the offsetted seed point instead of the offsetted wanted
sampling point.

- cannot change stream compression after construction.

ENH: added scalarField hypot() function

- Now accept '/' when reading variables without requiring
  a surrounding '{}'

- fix some degenerate parsing cases when the first character is
  already bad.

  Eg, $"abc" would have previously parsed as a <$"> variable, even
  although a double quote is not a valid variable character.

  Now emits a warning and parses as a '$' token and a string token.

- avoid the name eval(), since this collides with the identical
  macro name if m4 is used sometime in the future

- add toScalar evaluation, embedded as "${{EXPR}}".

  For example,

    "repeat ${{5 * 7}} times or ${{ pow(3, 10) }}"

- use direct string concatenation if primitive entry is only a string
  type. This prevents spurious quotes from appearing in the expansion.

     radius  "(2+4)";
     angle   "3*15";
     #eval   "$radius*sin(degToRad($angle))";

     We want to have
         '(2+4)*sin(degToRad(3*15))'
     and not
         '"(2+4)"*sin(degToRad("3*15"))'

ENH: code refactoring

- refactored expansion code with low-level service routines now
  belonging to file-scope. All expansion routines use a common
  multi-parameter backend to handle with/without dictionary etc.
  This removes a large amount of code duplication.

- add floor/ceil/round methods
- support evaluation of sub-strings

STYLE: add blockMeshDict1.calc, blockMeshDict1.eval test dictionaries

- useful for testing and simple demonstration of equivalence

- SubField and SubList assign from zero
- SubField +=, -=, *=, /= operators

- SubList construct from UList (as per SubField)

  Note: constructing an anonymous SubField or SubList with a single
  parameter should use '{} instead of '()' to avoid compiler
  ambiguities.

- drop plugin support for Qt4 (old paraview)

- handle upcoming changes in VTK version naming in CMake files
  * VTK_MAJOR_VERSION becomes VTK_VERSION_MAJOR etc.