- allows reuse for other purposes

- the opposite problem from issue #762. Now we also test if the input
  token stream had any tokens at all.

- called by the dictionary get<> and readEntry() methods.

- simply combines (rootPath()/globalCaseName())

- replaces previous pointer conversion

- more consistent with dictionary method naming. The get<> or
  getList<> returns a value, doesn't read into a existing location.

- allows single or multiple entries

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

- can be used in predicate matching

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

- 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.

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

- supports copy append and move append

- simplifies usage.
  Support syncPar check on names() to detect inconsistencies.

- simplify readFields, ReadFields and other routines by using these
  new methods.

- this eliminates a degree of ambiguity when resolving a read() method
  in inherited classes.

- major() and minor() are GNU macros in sys/sysmacros.h
  and generates warning on some systems (eg, Ubuntu 18.04)

  use getMajor() and getMinor() as method names instead.

twoPhaseMixtureThermo writes the temperatures during construction only
for them to be read again immediately after by construction of the
individual phases' thermo models. When running with collated file
handling this behaviour is not thread safe. This change deactivates
threading for the duration of this behaviour.

Patch contributed by Mattijs Janssens

- add additional control via a Foam::infoDetailLevel flag, which is
  supported by a 'DetailLevel' macro.  Eg,

      DetailLevel << "some information" << nl

- When infoDetailLevel is zero, the stdout for all Foam::system() calls
  are also redirected to stderr to prevent child output from
  appearing on the parent.

- close stdin before exec in system call.

- this addresses issue #843

- Always used for optional dictionary entries, since these are individual
  values, and not meant to be embedded in a larger stream of tokens.

  Methods:
     - lookupOrDefault, lookupOrAddDefault, lookupOrDefaultCompat
     - readIfPresent, readIfPresentCompat

- Handling mandatory dictionary entries is slightly more complex,
  since these may be part of larger stream of tokens, and are often
  used in a constructor context. For example,

      word modelType(dict.lookup("type"));

  Or they are used without a definite context. For example,

      dict.lookup("format") >> outputFormat;

  Newly introduced methods for mandatory dictionary entries:
     - get, getCompat
     - read, readCompat

  In a constructor or assignment context:

      word modelType(dict.get<word>("type"));
      outputFormat = dict.lookup("format");

  without copy/move (similar to readIfPresent):

      dict.read("format", outputFormat);

- 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.

- consistency with make and more succinct.

- reduce code duplication in findEtcFiles.

- runTimeModifiable change to the dictionary not being propagated to
  the underlying functionObjects

- 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

- catch (value)
- forward declarations for operator<<()
- non-const access to Reaction name()
- spurious return statement

- this avoids some valgrind messages

      "Uninitialised byte(s) found during client check request"

- controlled by the the 'printExecutionFormat' InfoSwitch in
  etc/controlDict

      // Style for "ExecutionTime = " output
      // - 0 = seconds (with trailing 's')
      // - 1 = day-hh:mm:ss

   ExecutionTime = 112135.2 s  ClockTime = 113017 s

   ExecutionTime = 1-07:08:55.20  ClockTime = 1-07:23:37

- Callable via the new Time::printExecutionTime() method,
  which also helps to reduce clutter in the applications.
  Eg,

     runTime.printExecutionTime(Info);

  vs

     Info<< "ExecutionTime = " << runTime.elapsedCpuTime() << " s"
         << "  ClockTime = " << runTime.elapsedClockTime() << " s"
         << nl << endl;

--

ENH: return elapsedClockTime() and clockTimeIncrement as double

- previously returned as time_t, which is less portable.

- since PackedBoolList is now a compatibility typedef for bitSet,
  it is useful to have an additional means of distinction.

STYLE: simplify internal version tests and compiler defines.

- the API version is now conveyed via the OPENFOAM define directly.
  The older OPENFOAM_PLUS define is provided for existing code.

- flags the following type of problems:

  * mismatches:

        keyword  mismatch ( set of { brackets ) in the } entry;

  * underflow (too many closing brackets:

        keyword  too many ( set of ) brackets ) in ) entry;

- a missing semi-colon

        dict
        {
           keyword  entry with missing semi-colon
        }

  will be flagged as 'underflow', since it parses through the '}' but
  did not open with it.

Max monitoring depth is 60 levels of nesting, to avoid incurring any
memory allocation.