Reorganized layout of SpikeDisplayCanvas

Source/Processors/Editors/GenericEditor.cpp

Source/Processors/Editors/GenericEditor.h

Source/Processors/Editors/SpikeDetectorEditor.cpp

Source/Processors/Editors/SpikeDisplayEditor.cpp

Source/Processors/Editors/SpikeDisplayEditor.h

Source/Processors/GenericProcessor.cpp

Source/Processors/GenericProcessor.h

Source/Processors/SpikeDetector.cpp

Source/Processors/SpikeDisplayNode.cpp

Source/Processors/SpikeDisplayNode.h

Source/Processors/Visualization/LfpDisplayCanvas.cpp

Source/Processors/Visualization/OpenGLCanvas.cpp

Source/Processors/Visualization/SpikeDisplayCanvas.cpp

Source/Processors/Visualization/SpikeDisplayCanvas.h