GUIEditor clears now existing elements before loading new ones.

Thanks @Artem Shoobovych for the patch (#323)
I changed it a bit, but basically same idea.


git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6210 dfc29bdd-3216-0410-991c-e03cc46cb475

tools/GUIEditor/CGUIEditWorkspace.h

@@ -46,6 +46,9 @@ namespace gui
 		//! Removes a child.
 		virtual void removeChild(IGUIElement* child);
 
+		//! Remove all gui elements from parent except this one
+		virtual void clearParentElements();
+
 		//! draws the element and its children
 		virtual void draw();