ENH: runTimePostProcessing - added option to clear/remove objects after use

src/runTimePostProcessing/CMakeLists-Common.txt

src/runTimePostProcessing/fieldVisualisationBase.C

src/runTimePostProcessing/fieldVisualisationBase.H

src/runTimePostProcessing/functionObjectBase.C

src/runTimePostProcessing/functionObjectBase.H

src/runTimePostProcessing/functionObjectCloud.C

src/runTimePostProcessing/functionObjectCloud.H

src/runTimePostProcessing/functionObjectLine.C

src/runTimePostProcessing/functionObjectLine.H

src/runTimePostProcessing/functionObjectSurface.C

src/runTimePostProcessing/functionObjectSurface.H

src/runTimePostProcessing/geometryBase.H

src/runTimePostProcessing/geometrySurface.C

src/runTimePostProcessing/geometrySurface.H

src/runTimePostProcessing/runTimePostProcessing.C

src/runTimePostProcessing/scene.H

src/runTimePostProcessing/text.C

src/runTimePostProcessing/text.H