Complete refactor of project file structure

Fix incorrect handing of default node parameters in SSD subscription.
Fix unable to parse some Clash rule-providers (#289).
Fix not filtering inline comments in some Surge rulesets. (#285)
Add Cron task options.
Add clean context option for persisting a JS context across the whole request.
Replace JS engine with QuickJS.

src/server/webserver.h

@@ -0,0 +1,46 @@
+#ifndef WEBSERVER_H_INCLUDED
+#define WEBSERVER_H_INCLUDED
+
+#include <string>
+#include <map>
+
+#include "../utils/map_extra.h"
+
+struct Request
+{
+    std::string method;
+    std::string url;
+    std::string argument;
+    string_icase_map headers;
+    std::string postdata;
+};
+
+struct Response
+{
+    int status_code = 200;
+    std::string content_type;
+    string_icase_map headers;
+};
+
+using response_callback = std::string (*)(Request&, Response&); //process arguments and POST data and return served-content
+
+#define RESPONSE_CALLBACK_ARGS Request &request, Response &response
+
+struct listener_args
+{
+    std::string listen_address;
+    int port;
+    int max_conn;
+    int max_workers;
+    void (*looper_callback)() = nullptr;
+    uint32_t looper_interval = 200;
+};
+
+void append_response(const std::string &method, const std::string &uri, const std::string &content_type, response_callback response);
+void append_redirect(const std::string &uri, const std::string &target);
+void reset_redirect();
+int start_web_server(void *argv);
+int start_web_server_multi(void *argv);
+void stop_web_server();
+
+#endif // WEBSERVER_H_INCLUDED