Doc: NR remove 5.1.7 (issue4839061)

[tdanielsmusic]

James
My suggestion was to remove the *material* in 5.1.7 and replace it with
material from 5.4.3, removing 5.4.3 as a section.  The reference at the
end of the material from 5.4.3 will need to be removed.  Also, following
Neil's reminder, we need to expand the documentation of the use of
\accepts in 5.1.7 too, using his neat example.
Trevor


http://codereview.appspot.com/4839061/