tooltip-mode docstring

[Luc Teirlinck]

The docstring of tooltip-mode does not seem very helpful.  It
misleadingly suggests that if you disable it, you do not get to see
any help-text on mouse-over, whereas tooltip-mode only determines
_where_ you see that thext rather than _whether_ you see it.

Unless there are objections, I plan to install the following doc fix:

===File ~/tooltip-diff======================================
*** tooltip.el  20 Dec 2005 15:59:43 -0600      1.72
--- tooltip.el  09 Jan 2006 21:14:26 -0600      
***************
*** 48,54 ****
  
  (define-minor-mode tooltip-mode
    "Toggle Tooltip display.
! With ARG, turn tooltip mode on if and only if ARG is positive."
    :global t
    :init-value (not (or noninteractive
                       emacs-basic-display
--- 48,57 ----
  
  (define-minor-mode tooltip-mode
    "Toggle Tooltip display.
! With ARG, turn tooltip mode on if and only if ARG is positive.
! When this minor mode is enabled, Emacs displays help text
! in a pop-up tooltip on mouse-over.  When it is disabled,
! Emacs displays the help text in the echo area instead."
    :global t
    :init-value (not (or noninteractive
                       emacs-basic-display
============================================================