change cmakelists and gitignore, commit third librarys source

include/UtilTool.h

@@ -0,0 +1,9 @@
+#include <iostream>
+#include <array>
+
+class UtilTool
+{
+public:
+    constexpr static std::array<std::string, 2> ImageType{"jpg","png"};
+    static bool CheckFileIsImage(const std::string& filename);
+};