EKF: remove dependecies and allow ekf to be built as standalone shared lib

EKF/mathlib.h

@@ -0,0 +1,19 @@
+#ifndef MATHLIB_H
+#define MATHLIB_H
+#ifdef POSIX_SHARED
+#include <Eigen/Dense>
+#include <algorithm>
+#define M_PI_F 3.14159265358979323846f
+
+namespace math {
+	using namespace Eigen;
+	using namespace std;
+
+	float constrain(float &val, float min, float max);
+	float radians(float degrees);
+	float degrees(float radians);
+}
+#else
+#include <mathlib/mathlib.h>
+#endif //POSIX_SHARED
+#endif //MATHLIB_H