Continue work on png writer.

test/image/TestPngWriter.cpp

@@ -1,7 +1,7 @@
 #include "Image.h"
 #include "PngWriter.h"
 
-
+#include "File.h"
 #include "BitStream.h"
 #include "ImagePrimitives.h"
 
@@ -24,5 +24,15 @@ int main()
     writer.setPath("test.png");
     writer.write(image);
 
+    File test_file("test.png");
+    test_file.SetAccessMode(File::AccessMode::Read);
+    test_file.Open(true);
+
+    while(auto byte = test_file.readNextByte())
+    {
+        std::cout << static_cast<unsigned>(*byte) << std::endl;
+    }
+    test_file.Close();
+
     return 0;
 }