ENH: adding hook adjustTimeStep to function objects. The hook is called in

Time::adjustDeltaT(). It allows function objects to manipulate the time step to
    dump at adjustable times. The following options are available for output in
    function objects: timeStep, outputTime, adjustableTime, runTime, clockTime
    and cpuTime.

src/OpenFOAM/db/functionObjects/functionObjectList/functionObjectList.H

@@ -166,6 +166,9 @@ public:
         //- Called when time was set at the end of the Time::operator++
         virtual bool timeSet();
 
+        //- Called at the end of Time::adjustDeltaT() if adjustTime is true
+        virtual bool adjustTimeStep();
+
         //- Read and set the function objects if their data have changed
         virtual bool read();