Fixed update of stream closed status in case of data frames.

It was possible that a client sent a data frame with close=true, but the half close of the
stream was delayed until after all the data bytes were sent.
The server received the data bytes and sent a reply with close=true that could have been
processed before the stream was actually half closed by the data frame delayed update,
and this generated a race condition.
Now the close status is updated before sending the data (like all other frames), but the
stream is removed only when data has been fully sent.

src/main/java/org/eclipse/jetty/spdy/StandardSession.java

@@ -718,7 +718,6 @@ public class StandardSession implements ISession, Parser.Listener, ISession.Cont
             }
             else
             {
-                stream.updateCloseState(data.isClose());
                 if (stream.isClosed())
                     removeStream(stream);
             }

src/main/java/org/eclipse/jetty/spdy/StandardStream.java

@@ -247,9 +247,7 @@ public class StandardStream implements IStream
     @Override
     public void data(DataInfo dataInfo)
     {
-        // We do not update the close state here, because the dataInfo may
-        // generate several frames and in the middle we may receive window
-        // updates, so we need the stream to update the window size
+        updateCloseState(dataInfo.isClose());
         session.data(this, dataInfo);
     }