the mouse wheel. This adds a short period after each mouse wheel
scroll event where a click on the mouse wheel button is ignored.
(mouse-wheel-click-event, mouse-wheel-inhibit-click-time): New customs.
(mouse-wheel-click-button, mwheel-inhibit-click-event-timer): New vars.
(mwheel-inhibit-click-timeout,mwheel-filter-click-events): New defuns.
(mwheel-scroll): Add mwheel-filter-click-events as pre-command-hook.
Start mwheel-inhibit-click-event-timer with timeout handler
mwheel-inhibit-click-timeout.
(mouse-wheel-up-button, mouse-wheel-down-button): Obsolete.
(mouse-wheel-up-event, mouse-wheel-down-event): New vars.
(mouse-wheel-follow-mouse): Change default to t.
(mwheel-event-button): Return the basic event symbol.
(mwheel-scroll): Work with non-mouse events.
(mouse-wheel-mode): Use the new vars.
(mwheel-install): Obey `uninstall'.
scrolling speed, fix an unwind-protect.
(mouse-wheel-scroll-amount): Now a three-element list.
(mouse-wheel-scroll-down-slow, mouse-wheel-scroll-up-slow)
(mouse-wheel-scroll-down-normal, mouse-wheel-scroll-up-normal)
(mouse-wheel-scroll-down-fast, mouse-wheel-scroll-up-fast): New functions.
event-modifiers before looking up in `mouse-wheel-scroll-amount'.
If there's no applicable modifiers entry in the alist in
`mouse-wheel-scroll-amount', fall back to the default, not to
nil (which causes full screen scrolls).
(mouse-wheel-follow-mouse): Renamed from `mwheel-follow-mouse'.
(mouse-wheel-mode): Use (featurep 'xemacs) instead of
string-matching against the version string.
