D7: editor multi-cursor support

Add secondary_cursors field to Editor with insert_char_multi,
delete_back_multi, delete_forward_multi methods. Right-to-left
processing ensures position shifts don't corrupt earlier insertions.

7 new tests: add/clear, all_positions, insert, delete_back,
delete_forward, unicode, duplicate-add.

local/recipes/tools/diffutils/source/gnulib-tests/sockets.h

@@ -0,0 +1,66 @@
+/* sockets.h - wrappers for Windows socket functions
+
+   Copyright (C) 2008-2017 Free Software Foundation, Inc.
+
+   This program is free software: you can redistribute it and/or modify
+   it under the terms of the GNU General Public License as published by
+   the Free Software Foundation; either version 3 of the License, or
+   (at your option) any later version.
+
+   This program is distributed in the hope that it will be useful,
+   but WITHOUT ANY WARRANTY; without even the implied warranty of
+   MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+   GNU General Public License for more details.
+
+   You should have received a copy of the GNU General Public License
+   along with this program.  If not, see <http://www.gnu.org/licenses/>.  */
+
+/* Written by Simon Josefsson */
+
+#ifndef SOCKETS_H
+#define SOCKETS_H 1
+
+#define SOCKETS_1_0 0x0001
+#define SOCKETS_1_1 0x0101
+#define SOCKETS_2_0 0x0002
+#define SOCKETS_2_1 0x0102
+#define SOCKETS_2_2 0x0202
+
+int gl_sockets_startup (int version)
+#ifndef WINDOWS_SOCKETS
+  _GL_ATTRIBUTE_CONST
+#endif
+  ;
+
+int gl_sockets_cleanup (void)
+#ifndef WINDOWS_SOCKETS
+  _GL_ATTRIBUTE_CONST
+#endif
+  ;
+
+/* This function is useful it you create a socket using gnulib's
+   Winsock wrappers but needs to pass on the socket handle to some
+   other library that only accepts sockets. */
+#ifdef WINDOWS_SOCKETS
+
+# include <sys/socket.h>
+
+# if GNULIB_MSVC_NOTHROW
+#  include "msvc-nothrow.h"
+# else
+#  include <io.h>
+# endif
+
+static inline SOCKET
+gl_fd_to_handle (int fd)
+{
+  return _get_osfhandle (fd);
+}
+
+#else
+
+# define gl_fd_to_handle(x) (x)
+
+#endif /* WINDOWS_SOCKETS */
+
+#endif /* SOCKETS_H */