Brought Math::Quaternion<GLfloat> into Magnum namespace as Quaternion.

src/Magnum.h

@@ -64,6 +64,8 @@ namespace Math {
     template<class> class Matrix3;
     template<class> class Matrix4;
 
+    template<class> class Quaternion;
+
     template<class T> constexpr T deg(T value);
     template<class T> constexpr T rad(T value);
     template<class T> class Constants;
@@ -117,6 +119,9 @@ typedef Math::Matrix3<GLfloat> Matrix3;
 /** @brief 4x4 floating-point matrix */
 typedef Math::Matrix4<GLfloat> Matrix4;
 
+/** @brief Quaternion */
+typedef Math::Quaternion<GLfloat> Quaternion;
+
 /** @brief Floating-point constants */
 /* Using float instead of GLfloat to not break KDevelop autocompletion */
 typedef Math::Constants<float> Constants;

src/Math/Quaternion.h

@@ -30,7 +30,11 @@
 
 namespace Magnum { namespace Math {
 
-/** @brief %Quaternion */
+/**
+@brief %Quaternion
+
+@see Magnum::Quaternion
+*/
 template<class T> class Quaternion {
     public:
         /**