AP_OpticalFlow: standardize inclusion of libaries headers

This commit changes the way libraries headers are included in source files:

 - If the header is in the same directory the source belongs to, so the
 notation '#include ""' is used with the path relative to the directory
 containing the source.

 - If the header is outside the directory containing the source, then we use
 the notation '#include <>' with the path relative to libraries folder.

Some of the advantages of such approach:

 - Only one search path for libraries headers.

 - OSs like Windows may have a better lookup time.

libraries/AP_OpticalFlow/AP_OpticalFlow_HIL.cpp

@@ -19,7 +19,7 @@
  * This is a dummy class, with the work done in setHIL()
  */
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #include "OpticalFlow.h"
 
 extern const AP_HAL::HAL& hal;

libraries/AP_OpticalFlow/AP_OpticalFlow_Linux.cpp

@@ -22,7 +22,7 @@
  *
  */
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #include "OpticalFlow.h"
 
 #define PX4FLOW_DEBUG 1

libraries/AP_OpticalFlow/AP_OpticalFlow_Linux.h

@@ -9,7 +9,7 @@
 #define AP_OpticalFlow_Linux_H
 
 #include "OpticalFlow.h"
-#include <AP_Math.h>
+#include <AP_Math/AP_Math.h>
 
 class AP_OpticalFlow_Linux : public OpticalFlow_backend
 {

libraries/AP_OpticalFlow/AP_OpticalFlow_PX4.cpp

@@ -19,7 +19,7 @@
  *
  */
 
-#include <AP_HAL.h>
+#include <AP_HAL/AP_HAL.h>
 #include "OpticalFlow.h"
 
 #if CONFIG_HAL_BOARD == HAL_BOARD_PX4

libraries/AP_OpticalFlow/OpticalFlow.cpp

@@ -1,6 +1,6 @@
 /// -*- tab-width: 4; Mode: C++; c-basic-offset: 4; indent-tabs-mode: nil -*-
 
-#include <AP_Progmem.h>
+#include <AP_Progmem/AP_Progmem.h>
 #include "OpticalFlow.h"
 
 extern const AP_HAL::HAL& hal;

libraries/AP_OpticalFlow/OpticalFlow.h

@@ -20,8 +20,8 @@
  *       Code by Randy Mackay. DIYDrones.com
  */
 
-#include <AP_HAL.h>
-#include <AP_Math.h>
+#include <AP_HAL/AP_HAL.h>
+#include <AP_Math/AP_Math.h>
 
 class OpticalFlow_backend;
 

libraries/AP_OpticalFlow/examples/AP_OpticalFlow_test/AP_OpticalFlow_test.cpp

@@ -3,32 +3,32 @@
  *  Code by Randy Mackay. DIYDrones.com
  */
 
-#include <AP_Common.h>
-#include <AP_Progmem.h>
-#include <AP_Param.h>
-#include <StorageManager.h>
-#include <AP_Math.h>
-#include <AP_HAL.h>
-#include <AP_HAL_AVR.h>
-#include <AP_HAL_SITL.h>
-#include <AP_AHRS.h>
-#include <AP_Compass.h>
-#include <AP_Declination.h>
-#include <AP_Airspeed.h>
-#include <GCS_MAVLink.h>
-#include <AP_Vehicle.h>
-#include <AP_Notify.h>
-#include <DataFlash.h>
-#include <AP_GPS.h>
-#include <AP_InertialSensor.h>
-#include <AP_ADC.h>
-#include <AP_ADC_AnalogSource.h>
-#include <Filter.h>
-#include <AP_Baro.h>
-#include <AP_OpticalFlow.h>
-#include <AP_Mission.h>
-#include <AP_Terrain.h>
-#include <AP_BattMonitor.h>
+#include <AP_Common/AP_Common.h>
+#include <AP_Progmem/AP_Progmem.h>
+#include <AP_Param/AP_Param.h>
+#include <StorageManager/StorageManager.h>
+#include <AP_Math/AP_Math.h>
+#include <AP_HAL/AP_HAL.h>
+#include <AP_HAL_AVR/AP_HAL_AVR.h>
+#include <AP_HAL_SITL/AP_HAL_SITL.h>
+#include <AP_AHRS/AP_AHRS.h>
+#include <AP_Compass/AP_Compass.h>
+#include <AP_Declination/AP_Declination.h>
+#include <AP_Airspeed/AP_Airspeed.h>
+#include <GCS_MAVLink/GCS_MAVLink.h>
+#include <AP_Vehicle/AP_Vehicle.h>
+#include <AP_Notify/AP_Notify.h>
+#include <DataFlash/DataFlash.h>
+#include <AP_GPS/AP_GPS.h>
+#include <AP_InertialSensor/AP_InertialSensor.h>
+#include <AP_ADC/AP_ADC.h>
+#include <AP_ADC_AnalogSource/AP_ADC_AnalogSource.h>
+#include <Filter/Filter.h>
+#include <AP_Baro/AP_Baro.h>
+#include <AP_OpticalFlow/AP_OpticalFlow.h>
+#include <AP_Mission/AP_Mission.h>
+#include <AP_Terrain/AP_Terrain.h>
+#include <AP_BattMonitor/AP_BattMonitor.h>
 
 const AP_HAL::HAL& hal = AP_HAL_BOARD_DRIVER;