Manual updates for window changes.

Manual updates for window changes.

* doc/emacs/windows.texi (Basic Window): Add xref to Cursor Display.
(Split Window): Document negative arg for splitting commands.
(Other Window): Document mouse-1 in text area of window.
(Change Window): Don't mention window attributes, since they
aren't defined.  C-x 1 can't be used with minibuffer windows.
Windows are no longer auto-deleted.
(Window Choice): Add xref to Choosing Window in Lisp manual.
(Window Convenience): Note that windmove disables shift-selection.
Move M-x compare-windows here from Other Window node.

* doc/emacs/custom.texi (Mouse Buttons):
* doc/emacs/search.texi (Isearch Scroll):
* doc/emacs/windows.texi (Split Window): Use new names split-window-below
and split-window-right.

* doc/lispref/windows.texi (Basic Windows): Clarify various definitions.
Treat window-normalize-* as internal; don't document them.
(Windows and Frames): Various clarifications, e.g. non-live
windows also belong to frames.  Fix window-list description.
Simplify window nesting example.
(Splitting Windows, Window Configurations): Use
split-window-below.