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.

- allows logging min/max without creating any files

- readFields works seamlessly on-the-fly and as postprocessor
- new surfaceInterpolateFields to create interpolated field
- writeRegisteredObject only check upon writing, not upon startup
- add min,max to faceSource

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