Fixing doxygen layout for ISceneNode. Same should probably be done throughout.

Our current member function documentation look often rather strange. The reason is that the first 
line in multi-line comment is handled special (it get's a box around it). So in the cases where we use
this for \param or have sentences starting in that line and continuing in the next it always looks broken.
Please click for example through IGUIElement documenation which is not yet fixed to see this.
Also links to enums don't seem to need @ref but just ::my_enum_name.  


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@4746 dfc29bdd-3216-0410-991c-e03cc46cb475

include/IGUIElement.h

@@ -69,7 +69,7 @@ public:
 	}
 
 
-	//! Returns the relative rectangle of this element.
+	//! Returns the position rectangle relative to it's parent
 	core::rect<s32> getRelativePosition() const
 	{
 		return RelativeRect;
@@ -717,10 +717,8 @@ public:
 
 
 	//! Returns the type of the gui element.
-	/** This is needed for the .NET wrapper but will be used
-	later for serializing and deserializing.
-	If you wrote your own GUIElements, you need to set the type for your element as first parameter
-	in the constructor of IGUIElement. For own (=unknown) elements, simply use EGUIET_ELEMENT as type */
+	/** If you wrote your own GUIElements, you need to set the type for your element as first parameter
+	in the constructor of IGUIElement. For own (=unknown) elements, use ::EGUIET_ELEMENT as type */
 	EGUI_ELEMENT_TYPE getType() const
 	{
 		return Type;
@@ -742,8 +740,8 @@ public:
 
 
 	//! Returns the type name of the gui element.
-	/** This is needed serializing elements. For serializing your own elements, override this function
-	and return your own type name which is created by your IGUIElementFactory */
+	/** This is needed for serializing elements. For serializing your own elements, override this function
+	and return your own type name which is created by your irr::gui::IGUIElementFactory */
 	virtual const c8* getTypeName() const
 	{
 		return GUIElementTypeNames[Type];