Author: Dan Poltawski
CONTRIB-350 - Update book module to use new navigation structure & admin settings in 1.9
http://git.moodle.org/gw?p=moodle.git;a=commit;h=50c53e20493166bee6dbc720452f4315199b979f
http://github.com/moodle/moodle/commit/50c53e20493166bee6dbc720452f4315199b979f
+ 2.3 en [book_tocwidth,book]