Add libhv and test http client

vendor/libhv/include/hv/hurl.h

@@ -0,0 +1,34 @@
+#ifndef HV_URL_H_
+#define HV_URL_H_
+
+#include <string> // import std::string
+
+#include "hexport.h"
+
+class HV_EXPORT HUrl {
+public:
+    static std::string escape(const std::string& str, const char* unescaped_chars = "");
+    static std::string unescape(const std::string& str);
+    static inline std::string escapeUrl(const std::string& url) {
+        return escape(url, ":/@?=&#+");
+    }
+
+    HUrl() : port(0) {}
+    ~HUrl() {}
+
+    void reset();
+    bool parse(const std::string& url);
+    const std::string& dump();
+
+    std::string url;
+    std::string scheme;
+    std::string username;
+    std::string password;
+    std::string host;
+    int         port;
+    std::string path;
+    std::string query;
+    std::string fragment;
+};
+
+#endif // HV_URL_H_