Merge pull request #468 from Dmitry-Me/reuseDeleteChild

Reuse DeleteChild()

tinyxml2.cpp

@@ -760,11 +760,7 @@ void XMLNode::DeleteChildren()
 {
     while( _firstChild ) {
         TIXMLASSERT( _lastChild );
-        TIXMLASSERT( _firstChild->_document == _document );
-        XMLNode* node = _firstChild;
-        Unlink( node );
-
-        DeleteNode( node );
+        DeleteChild( _firstChild );
     }
     _firstChild = _lastChild = 0;
 }