Move/add window-buffer-related functions to window.el.

Move/add window-buffer-related functions to window.el.

* buffer.c: New Lisp objects Qbuffer_list_update_hook and
Qclone_number.  Remove external declaration of Qdelete_window.
(Fbuffer_list): Rewrite doc-string.  Minor restructuring of
code.
(Fget_buffer_create, Fmake_indirect_buffer, Frename_buffer): Run
Qbuffer_list_update_hook if allowed.
(Fother_buffer): Rewrite doc-string.  Major rewrite for new
buffer list implementation.
(other_buffer_safely): New function.
(Fkill_buffer): Replace call to replace_buffer_in_all_windows by
calls to replace_buffer_in_windows and
replace_buffer_in_windows_safely.  Run Qbuffer_list_update_hook
if allowed.
(record_buffer): Inhibit quitting and rewrite using quittable
functions.  Run Qbuffer_list_update_hook if allowed.
(Frecord_buffer, Funrecord_buffer): New functions.
(switch_to_buffer_1, Fswitch_to_buffer): Remove.  Move
switch-to-buffer to window.el.
(bury-buffer): Move to window.el.
(Vbuffer_list_update_hook): New variable.

* lisp.h (other_buffer_safely): Add prototype in buffer.c
section.

* window.h (resize_frame_windows): Move up in code.
(Fwindow_frame): Remove EXFUN.
(replace_buffer_in_all_windows): Remove prototype.
(replace_buffer_in_windows_safely): Add prototype.

* window.c: Declare Qdelete_window static again.  Move down
declaration of select_count.
(Fnext_window, Fprevious_window): Rewrite doc-strings.
(Fother_window): Move to window.el.
(window_loop): Remove DELETE_BUFFER_WINDOWS and UNSHOW_BUFFER
cases.  Add REPLACE_BUFFER_IN_WINDOWS_SAFELY case.
(Fdelete_windows_on, Freplace_buffer_in_windows): Move to
window.el.
(replace_buffer_in_windows): Implement by calling
Qreplace_buffer_in_windows.
(replace_buffer_in_all_windows): Remove with some functionality
moved into replace_buffer_in_windows_safely.
(replace_buffer_in_windows_safely): New function.
(select_window_norecord, select_frame_norecord): Move in front
of run_window_configuration_change_hook.  Remove now obsolete
declarations.
(Fset_window_buffer): Rewrite doc-string.  Call
Qrecord_window_buffer.
(keys_of_window): Move binding for other-window to window.el.

* loadup.el (top-level): Load window before files for the sake
of replace-buffer-in-windows.

* files.el (read-buffer-to-switch)
(switch-to-buffer-other-window)
(switch-to-buffer-other-frame, display-buffer-other-frame): Move
to window.el.

* simple.el (get-next-valid-buffer, last-buffer, next-buffer)
(previous-buffer): Move to window.el.

* bindings.el (unbury-buffer): Move to window.el.

* window.el (delete-other-windows-vertically): Move after
definition of delete-other-windows.
(other-window, delete-windows-on, replace-buffer-in-windows):
Move here from window.c.
(record-window-buffer, unrecord-window-buffer)
(set-window-buffer-start-and-point, switch-to-prev-buffer)
(switch-to-next-buffer): New functions.
(get-next-valid-buffer, last-buffer, next-buffer): Move here
from simple.el.  Call switch-to-next-buffer.
(previous-buffer): Move here from simple.el.  Call
switch-to-prev-buffer.
(bury-buffer): Move here from buffer.c.  Switch to previous
buffer when window cannot be deleted.
(unbury-buffer): Move here from bindings.el.
(ctl-x-map): Move binding for other-window from window.c to
here.
(read-buffer-to-switch, switch-to-buffer-other-window)
(switch-to-buffer-other-frame): Move here from files.el.
(normalize-buffer-to-switch-to): New functions.
(switch-to-buffer): Move here from buffer.c.  Use
read-buffer-to-switch and normalize-buffer-to-switch-to.