Removed cut-buffer code.

Removed cut-buffer code.

* lisp/mouse-sel.el (mouse-sel-get-selection-function):
x-cut-buffer-or-selection-value renamed to x-selection-value.
(x-select-text): Optional push removed.

* lisp/select.el (x-get-cut-buffer, x-set-cut-buffer): Remove.

* lisp/simple.el (interprogram-cut-function): Remove mention of PUSH.

* lisp/w32-fns.el (x-last-selected-text):
x-cut-buffer-or-selection-value renamed to x-selection-value.
(x-cut-buffer-max): Remove.
(x-select-text): Remove argument PUSH, update documentation.

* lisp/emacs-lisp/cl-macs.el (x-get-cutbuffer, x-get-cut-buffer): Remove.

* lisp/term/ns-win.el (x-setup-function-keys, ns-last-selected-text):
x-cut-buffer-or-selection-value renamed to x-selection-value
(x-selection-value): Renamed from x-cut-buffer-or-selection-value.
(x-select-text): Remove argument PUSH, update documentation.

* lisp/term/pc-win.el (x-last-selected-text):
x-cut-buffer-or-selection-value renamed to x-selection-value
(x-select-text): Remove argument PUSH, update documentation.

* lisp/term/x-win.el: Update documentation for x-last-selected-text-*.
(x-last-selected-text-cut, x-last-selected-text-cut-encoded)
(x-last-cut-buffer-coding, x-cut-buffer-max): Remove.
(x-select-text): Remove argument PUSH, update documentation.  Remove
cut-buffer code.
(x-selection-value-internal): Was previously x-selection-value.
(x-selection-value): Renamed from x-cut-buffer-or-selection-value.
Update documentation, remove cut-buffer code.  Call
x-selection-value-internal.
(x-clipboard-yank): Call x-selection-value-internal.
(x-initialize-window-system): Remove setting of x-cut-buffer-max.

* src/xselect.c: Remove declaration of cut-buffer objects and functions.
(symbol_to_x_atom): Remove mapping to XA_CUT_BUFFERn.
(x_atom_to_symbol): Remove mapping to QCUT_BUFFERn.
(Fx_get_cut_buffer_internal, Fx_store_cut_buffer_internal)
(Fx_rotate_cut_buffers_internal): Remove.
(syms_of_xselect): Remove defsubr of above.
Remove intern of QCUT_BUFFERn.

* src/xterm.c (x_term_init): Don't set dpyinfo->cut_buffers_initialized.

* src/xterm.h (struct dpyinfo): Remove cut_buffers_initialized.