Correct deg to rad conversion inversion. Add additional functionality to mathlib to allow standalone compile without Limits.cpp and Limits.hpp files from PX4.

EKF/mathlib.h

@@ -41,18 +41,23 @@
 #ifndef MATHLIB_H
 #define MATHLIB_H
 #ifdef POSIX_SHARED
-#include <Eigen/Dense>
-#include <algorithm>
+// #include <Eigen/Dense>
+// #include <algorithm>
+// #include "Limits.hpp"
 #define M_PI_F 3.14159265358979323846f
+#define constexpr
 
 namespace math
 {
-using namespace Eigen;
+// using namespace Eigen;
 using namespace std;
 
+float min(float val1, float val2);
+float max(float val1, float val2);
 float constrain(float &val, float min, float max);
 float radians(float degrees);
 float degrees(float radians);
+
 }
 #else
 #include <mathlib/mathlib.h>