MSVC build fix & buildsystem overhaul

ext/base64/base64.h

@@ -0,0 +1,9 @@
+#ifndef __BASE64_H__
+#define __BASE64_H__
+
+#include <string>
+
+std::string base64_encode(unsigned char const* , unsigned int len);
+std::string base64_decode(std::string const& s);
+
+#endif