bug#15117: 24.3.50; doc of `(forward|backward)-*': state return value

[Drew Adams <drew.adams@oracle.com>]

> > These are NOT side-effect functions.  They modify nothing except
> > the cursor position.
> 
> How is that not a side-effect?

You are clearly arguing for the sake of arguing, now.

Everything in the universe has side effects.  Ohhmmmm.  It's true.

Motion functions are not what is typically meant by a side-effect
function.  They do not change the contents of the buffer, for
example, in the sense of `buffer-modified-p'.

These functions are like `goto-char' and `skip-chars-forward', as
mentioned in the bug report.  They are also like `forward-line',
another motion function whose return value we document.  And
`beginning-of-defun' - another.

By your (newfound) logic, you will presumably remove mention of
the return value from the doc for those functions.  The same
logic behind documenting their return value applies to these
other motion functions.