Fix missing format when writing Algorithm-based objects

Added a writeFormat() method to Algorithm which must be called by the
write() method of derived classes.

modules/features2d/src/kaze.cpp

@@ -159,6 +159,7 @@ namespace cv
 
         void write(FileStorage& fs) const
         {
+            writeFormat(fs);
             fs << "extended" << (int)extended;
             fs << "upright" << (int)upright;
             fs << "threshold" << threshold;