- allows use with any container with begin(), end() and where the
  "*iterator" dereference returns a label, which is used for indexing
  into the list of points.
  This container could be labelUList, bitSet, labelHashSet, etc

- takes a direct approach of determining which cells are cut and walks
  the cell faces directly to build the resulting surface.

- better handling of corner cases.
  * Avoids redundant points when the cut passes exactly through a
    mesh point.
  * Supresses generation of duplicates faces when the plane cut
    coincides exactly with a mesh face.

- for severely concave cells where the plane cuts a face multiple times
  there is currently no remedial action taken, except to note the
  failure and unwind the insertion of the corresponding points and
  faces.

- rework to use bitSet for more flexibility

- extract a list of the HashTable values, optionally sorted.

- when both min and max are required, this is more efficient than
  traversing the list twice.

Style changes:
    - use lookupObjectRef instead of using const_cast
    - use tmp::New factory

Style changes:
    - use lookupObjectRef instead of using const_cast
    - use tmp::New factory

Style changes:
    - use lookupObjectRef instead of using const_cast
    - use tmp::New factory

- signedDistance() method is like distance() but retains
  the positive/negative sign for the side of the plane.

- the sign() method returns the sign as -1,0,+1 integer for
  classification purposes where it is important to distinguish between
  a zero value and a positive value (eg, for cutting). Optional
  tolerance can be supplied to round for zero.

- refactor and inlined simple and frequently used methods.

- add boundBox faceCentre() method, which can be useful for creating
  clipping planes from a bounding box.
  Relocated treeBoundBox faceNormals to boundBox since they apply
  equally there - the meaning of the faces (x-min, x-max, etc)
  is the same, even if the point addressing for the faces differs.

- rationalized code dealing with extraction of name or indices from
  coordinateSystems, polyBoundaryMesh, faBoundaryMesh, fvBoundaryMesh,
  ZoneMesh to use internal implementations that allow direct
  searching/matching without building an intermediate list of names.

- simpler and more efficient handling of patch group matching.

- ensures that things stay synchronized when the processor domains
  have unequal looping.

- can be used in predicate matching

- getNameOp, getTypeOp for accessing the name() and type() of objects

- do not remove if the dictionary failed to load.
- do not remove if -blockTopology was used.

- centralizes IOobject handling and treatment of alternative locations.
  If an alternative file location is specified, it will be used instead.

- provide decompositionMethod::canonicalName instead of using
  "decomposeParDict" in various places.

- a second template parameter for the comparison value type instead of
  ListType::const_reference allows more generic comparison predicates.

- create a subset copy for sending on the processor patches instead of
  a List of unsigned ints. Reduces memory overhead and data transfer
  amount.

- treat as a List constant without requiring inclusion of ListOps.H

- replace use of emptyList<label>() with emptyLabelList directly.
  The emptyList<T>() casting is disallowed with many modern compilers
  and now marked as deprecated (expect early removal).

- relocate labelList typedef to List.H for more general access.
  Similar reasoning to having labelUList defined in UList.H

- makes for easier extraction of boundary values since it encapsulates
  start/size directly.

Eg,
    SubList<T>(allValues, patches.range());
or
    bitSet(blocked, patches.range(patchi));

Eg,
    processorPolyPatch pp = ...;

    UOPstream toNbr(pp.neighbProcNo(), pBufs);
    toNbr << PackedList<Width>(faceValues, pp.range());

- concise and more efficient

- allows direct 'hashing' of fixed lists. Eg, triFace

- allows for simpler unpacking of a full list, or list range into any
  sufficiently large integral type.

  For example,
    processorPolyPatch pp = ...;

    UOPstream toNbr(pp.neighbProcNo(), pBufs);
    toNbr << faceValues.unpack<char>(pp.range());

- add range support in globalIndex and SubField, SubDimensionedField

General:
    * -roots, -hostRoots, -fileHandler

Specific:
    * -to <coordinateSystem> -from <coordinateSystem>

- Display -help-compat when compatibility or ignored options are available

STYLE: capitalization of options text

- avoids compiler ambiguity when virtual methods such as
  IOdictionary::read() exist.

- the method was introduced in 1806, and was thus not yet widely used

- behaves the same as the valid() method, but can be queried directly
  like a normal raw pointer and as per std::unique_ptr.
  Eg,

      autoPtr<T> ptr = ...

      if (ptr) ...