[These changes were actually in the previous version.

[These changes were actually in the previous version.
This version is a doc fix.]

(mouse-drag-vertical-line): New function.
(mouse-scroll-min-lines): New variable.
(mouse-scroll-subr): Use it.

(mouse-drag-region): Record where the mouse drag has reached
and use that to adjust the drag event before replaying it.

(mouse-drag-region): Store the right end position
in the drag-event before replaying it at the end.

(mouse-skip-word): Skip complete symbol when over a
character with symbol syntax.