Refactor extras:

A new directory extras/ is added, and code not part of the official
public Beast interface is moved there.

test/http/message_v1.cpp

@@ -20,8 +20,8 @@
 // Test that header file is self-contained.
 #include <beast/http/message_v1.hpp>
 
-#include <beast/detail/unit_test/suite.hpp>
-#include <beast/detail/unit_test/thread.hpp>
+#include <beast/unit_test/suite.hpp>
+#include <beast/unit_test/thread.hpp>
 #include <beast/placeholders.hpp>
 #include <beast/streambuf.hpp>
 #include <beast/http.hpp>
@@ -39,15 +39,15 @@ public:
     using socket_type = boost::asio::ip::tcp::socket;
 
 private:
-    beast::detail::unit_test::suite& suite_;
+    unit_test::suite& suite_;
     boost::asio::io_service ios_;
     socket_type sock_;
     boost::asio::ip::tcp::acceptor acceptor_;
-    beast::detail::unit_test::thread thread_;
+    unit_test::thread thread_;
 
 public:
     sync_echo_http_server(
-            endpoint_type ep, beast::detail::unit_test::suite& suite)
+            endpoint_type ep, unit_test::suite& suite)
         : suite_(suite)
         , sock_(ios_)
         , acceptor_(ios_)
@@ -63,7 +63,7 @@ public:
         acceptor_.async_accept(sock_,
             std::bind(&sync_echo_http_server::on_accept, this,
                 beast::asio::placeholders::error));
-        thread_ = beast::detail::unit_test::thread(suite_,
+        thread_ = unit_test::thread(suite_,
             [&]
             {
                 ios_.run();
@@ -132,7 +132,7 @@ private:
     }
 };
 
-class message_test : public beast::detail::unit_test::suite
+class message_test : public beast::unit_test::suite
 {
 public:
     using endpoint_type = boost::asio::ip::tcp::endpoint;