Minor cleanup.

src/AbstractObject.h

@@ -36,9 +36,7 @@
 
 namespace Magnum {
 
-namespace Implementation {
+namespace Implementation { struct DebugState; }
-    struct DebugState;
-}
 
 /**
 @brief Base for all OpenGL objects

src/Implementation/DebugState.h

@@ -34,11 +34,8 @@ namespace Magnum { namespace Implementation {
 struct DebugState {
     DebugState(Context& context);
 
-    typedef std::string(*GetLabelImplementation)(GLenum, GLuint);
+    std::string(*getLabelImplementation)(GLenum, GLuint);
-    GetLabelImplementation getLabelImplementation;
+    void(*labelImplementation)(GLenum, GLuint, const std::string&);
-
-    typedef void(*LabelImplementation)(GLenum, GLuint, const std::string&);
-    LabelImplementation labelImplementation;
 
     GLint maxLabelLength;
 };