- The findObject() methods are template-typed and used to locate a
  particular Type/name combination.

  Eg,

      volScalarField* ptr = obr.findObject<volScalarField>("xyz");

- The findIOobject() methods are un-typed and use the name only.

  Eg,

      regIOobject* ptr = obr.findIOobject("xyz");

The typed versions will be most commonly used, but the un-typed lookup
can be useful in a templating.

- Simplified findObject* methods to use findIOobject* as the backend.

- similar to what erase() does, but as a mutable operation (#1180)

- replace basicThermo lookupAndCheckout (commit 880c9875) with
  the new objectRegistry::checkOut() method.

- implemented as lazy evaluation with an additional update() method.
  This avoids unnecessary changes until the values are actually
  required.

- apply mesh motion changes for momentum, volFieldValue,
  specieReactionRates function objects

- forwards to the underlying HashTable erase, but frees things owned
  by the registry as well (ie, performs a checkOut)

https://gcc.gnu.org/bugzilla/show_bug.cgi?id=56480

STYLE: avoid local variable name masking

- changed ensightOutput from a class solely comprising static methods to
  a namespace and added in sub-namespaces Detail and Serial.

  This makes it easier to "mix-in" functions at different levels.
  Refactored and combined some serial/parallel code where possible.

  The general ensightOutput namespace has now shifted to be in the
  fileFormats lib, while leaving volField outputs in the conversion lib
  and cloud outputs in the lagrangian-intermediate lib.

  The ensightCloud namespace is now simply folded into the new
  ensightOutput namespace.

  These changes clean up some code, reduce fragmentation and
  duplication and removes the previous libconversion dependency for
  sampling.

- use int for ensight nTypes constexpr

Note: issue #1176 is unaffected except for the change in file name:

   ensightOutputTemplates.C -> ensightOutputVolFieldTemplates.C

- allows localized extension of functionality

- improved the selection mechanism to include using a bitSet
  cell selection (more efficient and convenient).

  Use templated implementation internally to remove the previous
  reliance on a NullObject.

    Example usage:

    continuityError1
    {
        type        continuityError;
        libs        ("libfieldFunctionObjects.so");
        ...
        writeToFile yes;
        log         yes;
        phi         phi;
    }

Eg,
    #define FOAM_CONFIGURED_PROJECT_ETC "/usr/share/openfoam/etc"

This provides some easy to file patching locations, but is not yet
integrated in the build system at all.

- in some circumstances we need to pass a bool value upwards to the
  caller and know if the true/false value was set based on real input
  or is a default value.

  Eg, in the object::read() we might normally have

     enabled_(dict.readIfPresent(key, true));

  but would lose information about why the value is true/false.

  We can change that by using

     enabled_(dict.readIfPresent<Switch>(key, Switch::DEFAULT_ON));

  After which we can use this information is testing.

      if
      (
          child.enabled().nonDefault()
        ? child.enabled()
        : parent.enabled()
      )
      { ... }

   And thus enable output if the parent requested it explicitly or by
   default and it has not been explicitly disabled in the child.

  No difference when testing as a bool and the text representation
  of DEFAULT_ON / DEFAULT_OFF will simply be "true" / "false".

ENH: add construction of Switch from dictionary (similar to Enum)

- avoids removal of files and the dummy fallback

- as well as being more convenient to find, this is necessary when the
  OpenFOAM installation is without sources or tutorials

- Can result in inadvertent conversions where the user should really
  know or check if the pointer is valid prior to using.

- Still have several places to fix that are using the deprecated copy
  construct and copy assignment

- workaround for some old compilers many years ago, but no longer relevant

- in the previous version, a specification such as (U "U.*")
  would have selected the field name twice for writing

- can also be used for other purposes.
  Eg,

      if (ListOps::found(list, matcher))
      {
         ...
      }

  vs.

      if (!findStrings(matcher, list).empty())
      {
         ...
      }

- add compile-time detection of deprecated findIndex() function

- replace occurrences of findIndex() with the equivalent container
  method

- simply a functionObject with an additional Time reference, which is
  a combination frequently used by concrete functionObjects

- use for-range when iterating
- dictionary access/search methods
- autoPtr for memory management

- changed the sectorCoeffs keyword to 'point' from 'axisPt'
  for more similarity with other dictionaries.
  Continue to accept 'axisPt' for compatibility.