整理代码，添加部分注释

energy/include/energy/constant.h

@@ -14,7 +14,6 @@ const int SRC_WIDTH_CAMERA = 640;
 const int SRC_HEIGHT_CAMERA = 480;
 const int SRC_WIDTH = 320;
 const int SRC_HEIGHT = 240;
-const double PI = 3.1415926;
 const int CLOCKWISE = 1;
 const int ANTICLOCKWISE = -1;
 const float ATTACK_DISTANCE = 718;//cm

energy/include/energy/energy.h

@@ -9,6 +9,7 @@
 #include <opencv2/core/core.hpp>
 #include <opencv2/highgui/highgui.hpp>
 #include <opencv2/imgproc/imgproc.hpp>
+#include <constants.h>
 #include <stdio.h>
 #include <time.h>
 #include <sys/timeb.h>