Tune up static_buffer (API Change):

The static buffer is updated:

* reset() is no longer a member. Use b.consume(b.size()) instead.

* Simplified implementaton, uses asio instead of custom types

* Better stream performance: consuming the input makes room
  available in the output. This class is now suitable for
  HTTP reads.

These changes permit the static_buffer wrapper to adapt a user
memory buffer if desired, including a stack based array.
The static_buffer_n class may also be used for this purpose,
it comes with its own storage.

test/websocket/stream.cpp

@@ -1839,9 +1839,9 @@ public:
         BEAST_EXPECT(n < limit);
     }
 
-    void run() override
+    void
+    run() override
     {
-testHandshake();
         BOOST_STATIC_ASSERT(std::is_constructible<
             stream<socket_type>, boost::asio::io_service&>::value);