(mouse-delete-max-match): New function.

(mouse-delete-max-match): New function.
(mouse-choose-completion): Use that.  Now supports buffers
other than minibuffer.

(mouse-drag-region): Put the text on the kill ring.
Don't set mark if region is empty.
(mouse-yank-at-click): Set this-command.
(mouse-start-end): Fix double-click-on-closeparen case.
(mouse-save-then-kill): When used repeatedly at different places,
alter the nearer end of the region.  This applies regardless of how
the previous selection was made.
(mouse-drag-secondary, mouse-secondary-save-then-kill):
Rewrite for xterm-style dragging and extending.