- foamCleanPath now only splits the environment variable on ':', which
  allows other directories with spaces or '(..)' etc to pass through
  without major issue.

- The filter arguments are split on whitespace, colons or semi-colons.

- use keyType::option enum to consolidate searching options.
  These enumeration names should be more intuitive to use
  and improve code readability.

    Eg,   lookupEntry(key, keyType::REGEX);
    vs    lookupEntry(key, false, true);

  or

    Eg,   lookupEntry(key, keyType::LITERAL_RECURSIVE);
    vs    lookupEntry(key, true, false);

- new findEntry(), findDict(), findScoped() methods with consolidated
  search options for shorter naming and access names more closely
  aligned with other components. Behave simliarly to the
  methods lookupEntryPtr(), subDictPtr(), lookupScopedEntryPtr(),
  respectively. Default search parameters consistent with lookupEntry().

    Eg, const entry* e = dict.findEntry(key);
    vs  const entry* e = dict.lookupEntryPtr(key, false, true);

- added '*' and '->' dereference operators to dictionary searchers.

- seen with gcc-4.9.4, but not with gcc-7

- provide additional constructors from tmp for DimensionedField, FieldField

- use the dictionary 'get' methods instead of readScalar for
  additional checking

     Unchecked:  readScalar(dict.lookup("key"));
     Checked:    dict.get<scalar>("key");

- In templated classes that also inherit from a dictionary, an additional
  'template' keyword will be required. Eg,

     this->coeffsDict().template get<scalar>("key");

  For this common use case, the predefined getXXX shortcuts may be
  useful. Eg,

     this->coeffsDict().getScalar("key");

- not used by the ISstream parser, but suitable for other parsing
  methods where true/false concept should be distinguishable from
  integer values.

  Only constructed via the token::boolean() static method, not
  directly assignable.
  This avoids any potential ambiguities with label.

coordinate system improvements

See merge request OpenFOAM-plus!211

- avoids some doubled slashes

STYLE: simplify concatenation of processor directory names

- adjust member order in TimePaths to better packing

- local token shifting was missing when getting the next file chunk
  (while in the middle of parsing that text).

  As well as adding the correct shifting, also tag the local buffer
  with nullptr when it is done. Be extra paranoid and check the
  raw buffer range before passing off to std::string.

- for finer control of the '-help' output text

- this also removes the '-newTimes' option cruft from appearing
  everywhere. reconstructPar and redistributePar are unaffected by this
  since they define their own -newTimes option independently.

Compilation problems on older compilers

This reverts commit baf3e931.

    UPtrList::set(const label i, T* ptr);

No-op if the new pointer value is identical to the current content.
This avoid memory management issues.

- useful for customizing the behaviour of white/black lists depending
  on the type of the match.

- same as !isPattern(), but can be more readable.

- add wordRe enum state 'UNKNOWN', which has the identical value as
  'DETECT' but used for a return value.

overPimpleDymFoam

for correct run time reading.
Setting up twoSimpleRotors tutorial for smooth pressure
fluctuations