removed empty files

ex1/ABCEFG/skalar_stl/DenseMatrix.cpp

@@ -1,7 +0,0 @@
-
-#include <iostream>
-#include <vector>
-#include <cmath>
-#include <cassert>
-using namespace std;
-

ex1/ABCEFG/skalar_stl/DenseMatrix.h

@@ -1,4 +0,0 @@
-#pragma once
-
-#include <vector>
-using namespace std;

ex1/ABCEFG/skalar_stl/main.cpp

@@ -1,6 +1,5 @@
 #include "mylib.h"
 #include "timing.h"
-#include "DenseMatrix.h"
 
 #include <cassert>          // assert
 #include <vector>

ex1/ABCEFG/skalar_stl/mylib.cpp

@@ -1,6 +1,5 @@
 #include "mylib.h"
 #include "mayer_primes.h"
-#include "DenseMatrix.h"
 
 #include <cassert>          // assert
 #include <vector>