helper_functions: include defines for M_PI_PRECISE

The defintion of the custom symbol M_PI_PRECISE
was not included in one of the only places it's used.
Looks like a mistake that happened in
34c852255e
possibly because a lot of things are included
almost everywhere and if the include order
ligns up there are no compile errors.

src/lib/matrix/matrix/Quaternion.hpp

@@ -458,7 +458,7 @@ public:
 
 		for (size_t i = 0; i < 4; i++) {
 			if (std::fabs(q(i)) > FLT_EPSILON) {
-				return q * Type(matrix::sign(q(i)));
+				return q * Type(sign(q(i)));
 			}
 		}
 

src/lib/matrix/matrix/helper_functions.hpp

@@ -2,6 +2,8 @@
 
 #include <cmath>
 
+#include "math.hpp"
+
 namespace matrix
 {
 
@@ -41,7 +43,7 @@ Floating wrap_floating(Floating x, Floating low, Floating high)
 	return x - range * num_wraps;
 }
 
-}  // namespace detail
+} // namespace detail
 
 /**
  * Wrap single precision floating point value to stay in range [low, high)