functionObjects: rewritten to all be derived from 'functionObject'

- Avoids the need for the 'OutputFilterFunctionObject' wrapper
  - Time-control for execution and writing is now provided by the
    'timeControlFunctionObject' which instantiates the processing
    'functionObject' and controls its operation.
  - Alternative time-control functionObjects can now be written and
    selected at run-time without the need to compile wrapped version of
    EVERY existing functionObject which would have been required in the
    old structure.
  - The separation of 'execute' and 'write' functions is now formalized in the
    'functionObject' base-class and all derived classes implement the
    two functions.
  - Unnecessary implementations of functions with appropriate defaults
    in the 'functionObject' base-class have been removed reducing
    clutter and simplifying implementation of new functionObjects.
  - The 'coded' 'functionObject' has also been updated, simplified and tested.
  - Further simplification is now possible by creating some general
    intermediate classes derived from 'functionObject'.

src/OpenFOAM/db/functionObjects/functionObjectList/functionObjectList.C

@@ -27,6 +27,7 @@ License
 #include "Time.H"
 #include "mapPolyMesh.H"
 #include "argList.H"
+#include "timeControlFunctionObject.H"
 
 // * * * * * * * * * * * * Private Member Functions  * * * * * * * * * * * * //
 
@@ -354,7 +355,21 @@ bool Foam::functionObjectList::read()
                 FatalIOError.throwExceptions();
                 try
                 {
-                   foPtr = functionObject::New(key, time_, dict);
+                    if
+                    (
+                        dict.found("writeControl")
+                     || dict.found("outputControl")
+                    )
+                    {
+                        foPtr.set
+                        (
+                            new functionObjects::timeControl(key, time_, dict)
+                        );
+                    }
+                    else
+                    {
+                        foPtr = functionObject::New(key, time_, dict);
+                    }
                 }
                 catch (Foam::IOerror& ioErr)
                 {