Plugins: Removed unused versions of the Spatial Filter code

...gnal-processing/src/algorithms/ovpCApplySpatialFilter.cpp

...signal-processing/src/algorithms/ovpCApplySpatialFilter.h

...sing/src/box-algorithms/ovpCSpatialFilterBoxAlgorithm.cpp

...essing/src/box-algorithms/ovpCSpatialFilterBoxAlgorithm.h

...cessing/src/algorithms/filters/ovpCApplySpatialFilter.cpp

.../box-algorithms/filters/ovpCSpatialFilterBoxAlgorithm.cpp

plugins/processing/signal-processing/src/ovp_defines.h

plugins/processing/signal-processing/src/ovp_main.cpp