Export route_params base and task to silence MSVC C4251

Author: sentientsergio

include/boost/http_proto/server/router_types.hpp

@@ -17,6 +17,7 @@
 #include <boost/system/error_code.hpp>
 #include <exception>
 #include <string>
+#include <boost/http_proto/detail/config.hpp>
 #include <type_traits>
 
 namespace boost {
@@ -296,7 +297,7 @@ class basic_router;
     This is a required public base for any `Request`
     type used with @ref basic_router.
 */
-class route_params_base
+class BOOST_HTTP_PROTO_DECL route_params_base
 {
 public:
     /** The mount path of the current router

src/server/route_handler.cpp

@@ -20,6 +20,9 @@ route_params::
 {
 }
 
+route_params::task::
+~task() = default;
+
 route_params&
 route_params::
 status(