bug#11361: 24.1.50; doc string of `yank-pop-change-selection'

[Chong Yidong]

Eli Zaretskii <eliz@gnu.org> writes:

>>  "if you change `yank-pop-change-selection' to `t', then `M-y' saves
>>  the new yank to the clipboard."
>> 
>> That at least is clear.
>
> Is it?  What is a "yank"? what is a "clipboard"?  And why an option is
> called yank-pop-change-SELECTION when it affects the clipboard?  Etc.,
> etc., ad nauseam.

Pretty much.

I added a reference to `interprogram-cut-function' to the docstring,
which should clarify somewhat.  Closing the bug.