added resizer

lib/danbooru_image_resizer/GIFReader.h

@@ -0,0 +1,11 @@
+#ifndef GIF_READER_H
+#define GIF_READER_H
+
+#include "Reader.h"
+class GIF: public Reader
+{
+public:
+	bool Read(FILE *f, Resizer *resizer, char error[1024]);
+};
+
+#endif