Add IMeshBuffer::getType

Allows to find out which class a meshbuffer has.
I used the same kind of style as ISceneNode::getType. So using four CC codes and virtual functions (instead of type variable).

git-svn-id: svn://svn.code.sf.net/p/irrlicht/code/trunk@6330 dfc29bdd-3216-0410-991c-e03cc46cb475

include/CDynamicMeshBuffer.h

@@ -114,6 +114,12 @@ namespace scene
 			return PrimitiveType;
 		}
 
+		//! Returns type of the class implementing the IMeshBuffer
+		virtual EMESH_BUFFER_TYPE getType() const  IRR_OVERRIDE
+		{
+			return EMBT_DYNAMIC;
+		}
+
 		video::SMaterial Material;
 		core::aabbox3d<f32> BoundingBox;
 		//! Primitive type used for rendering (triangles, lines, ...)