BUG/MEDIUM: connection: Add a new CS_FL_ERR_PENDING flag to conn_streams.

Add a new flag to conn_streams, CS_FL_ERR_PENDING. This is to be set instead
of CS_FL_ERR in case there's still more data to be read, so that we read all
the data before closing.
diff --git a/include/types/connection.h b/include/types/connection.h
index d1819cc..3b7f4e1 100644
--- a/include/types/connection.h
+++ b/include/types/connection.h
@@ -81,6 +81,7 @@
 	CS_FL_ERROR         = 0x00000100,  /* a fatal error was reported */
 	CS_FL_RCV_MORE      = 0x00000200,  /* We may have more bytes to transfert */
 	CS_FL_WANT_ROOM     = 0x00000400,  /* More bytes to transfert, but not enough room */
+	CS_FL_ERR_PENDING   = 0x00000800,  /* An error is pending, but there's still data to be read */
 	CS_FL_EOS           = 0x00001000,  /* End of stream delivered to data layer */
 	CS_FL_REOS          = 0x00002000,  /* End of stream received (buffer not empty) */
 	CS_FL_WAIT_FOR_HS   = 0x00010000,  /* This stream is waiting for handhskae */