Implements #312 improved depth thresholds

applications/gui/src/camera.cpp

applications/gui/src/camera.hpp

applications/gui/src/src_window.cpp

components/common/cpp/include/ftl/cuda_common.hpp

components/operators/include/ftl/operators/mask_cuda.hpp

components/operators/include/ftl/operators/normals.hpp

components/operators/src/correspondence.cu

components/operators/src/mask.cpp

components/operators/src/mask.cu

components/operators/src/mls.cu

components/operators/src/mvmls.cpp

components/operators/src/mvmls_cuda.hpp

components/operators/src/normals.cpp

components/operators/src/segmentation.cpp

components/operators/src/segmentation.cu

components/operators/src/segmentation_cuda.hpp

components/operators/src/smoothing.cpp

components/renderers/cpp/include/ftl/cuda/mask.hpp

components/renderers/cpp/include/ftl/cuda/normals.hpp

components/renderers/cpp/include/ftl/render/CUDARender.hpp