bug#18296: 24.4.50; doc string of `whitespace-mode'

[Eli Zaretskii]

> Date: Sat, 30 Apr 2016 07:52:03 -0800 (GMT-08:00)
> From: Drew Adams <drew.adams@oracle.com>
> Cc: 18296@debbugs.gnu.org
> 
> There are N faces, nicely documented in `whitespace.el'.
> Why not put this info in the doc?

Because it is confusing, unless expanded and elaborated.

> `whitespace-space'            highlight SPACE
> `whitespace-hspace'           highlight HARD SPACE
> `whitespace-tab'              highlight TAB
> `whitespace-newline'          highlight NEWLINE char mapping
> `whitespace-trailing'         highlight trailing blanks
> `whitespace-line'             highlight "long" lines
> `whitespace-space-before-tab' highlight SPACEs before TAB
> `whitespace-indentation'      highlight 8+ SPACEs at bol
> `whitespace-big-indent'       highlight big indentation
> `whitespace-empty'            highlight empty lines at bob/eob
> `whitespace-space-after-tab'  highlight 8+ SPACEs after TAB

Quick: what's the difference between "big indentation" and "SPACEs
before TAB"?  How can you determine which one will be applied to a
specific line?  And what's the difference between "SPACE" and "HARD
SPACE"?  And what is "NEWLINE char mapping"?  Etc., etc.

IOW, someone should work on this stuff before it can be put in a doc
string.