Merge branch 'optical_flow'

controls/DataAnalysisTool/Tool/simplePlots.m

quad/src/computation_graph/computation_graph.c

quad/src/gen_diagram/network.dot

quad/src/gen_diagram/network.png

quad/src/graph_blocks/graph_blocks.c

quad/src/graph_blocks/graph_blocks.h

quad/src/graph_blocks/node_integrator.c

quad/src/graph_blocks/node_integrator.h

quad/src/quad_app/control_algorithm.c

quad/src/quad_app/hw_iface.h

quad/src/quad_app/initialize_components.c

quad/src/quad_app/log_data.c

quad/src/quad_app/log_data.h

quad/src/quad_app/quad_app.c

quad/src/quad_app/sensor.c

quad/src/quad_app/sensor_processing.c

quad/src/quad_app/timer.c

quad/src/quad_app/timer.h

quad/src/quad_app/type_def.h

quad/src/virt_quad/hw_impl_unix.h