(Selecting Windows): Clarify descriptions of

(Selecting Windows): Clarify descriptions of
with-selected-window and get-lru-window.
(Cyclic Window Ordering): Refer to particular frame when talking
about how splitting affects the ordering.
(Displaying Buffers): Fix descriptions of switch-to-buffer and
switch-to-buffer-other-window.  Explain how setting of
display-buffer-reuse-frames affects pop-to-buffer.
(Choosing Window): Clarify some details in descriptions of
display-buffer-reuse-frames, pop-up-frames, and
pop-up-frame-function.
(Dedicated Windows): Clarify some details.
(Textual Scrolling): Replace term vscroll by term vertical
scroll position.
(Vertical Scrolling): Fix typo.
(Window Hooks): Relate text on jit-lock-register to window
scrolling and size changes.