autofree: free global map consts and some vweb fixes

vlib/vweb/request.v

@@ -38,6 +38,7 @@ fn parse_request(mut reader io.BufferedReader) ?http.Request {
 			reader.read(mut body) or {}
 		}
 	}
+	h.free()
 
 	return http.Request{
 		method: method

vlib/vweb/vweb.v

@@ -298,6 +298,8 @@ pub fn run_app<T>(mut app T, port int) {
 	}
 }
 
+
+[manualfree]
 fn handle_conn<T>(mut conn net.TcpConn, mut app T) {
 	conn.set_read_timeout(30 * time.second)
 	conn.set_write_timeout(30 * time.second)