debugging_tools: Changed "Exiting " to "Exiting callable: ".
advanced_image_processing: Added the function extract_neurons, which will extract neurons from an image given a stack of masks.
neuron_volumina_viewer: Created a mechanism that provides an operator for max projection onto a source. Added MaxProjectionConstantSource and MaxProjectionConstantRequest for dealing with determing the max projection of a constant source (will not change or become dirty) along one dimension.