Resolves bug-report http://www.openfoam.org/mantisbt/view.php?id=1967

    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.

end of Time::operator++. This allows to know if the next timeIndex will be
a dumping time. The function object "partialWrite" modifyes the write option
of the those fields which will be written down at given intervals of the overall
outout times.

This reverts commit c5bea524.

This reverts commit b18f6cc1.

Created new functionObject for dsmcFields, renamed post processing utility dsmcFields to dsmcFieldsCalc and calling function object from there.

- added end() method to functionObject, functionObjectList & associated classes
- moved outputFilters from src/sampling -> src/OpenFOAM/db/functionObjects

 - it also found things like size_t instead of size_type in fileName class