[range] fix some minor typos in comments - fixes #7916

svn path=/trunk/boost/range/; revision=82594
[range] fixed #7926 (missing prototypes for lower_bound and upper_bound in docs)

svn path=/trunk/libs/range/; revision=82621
[range] allow iterator_range to be instantiated with a pointer to an array as the iterator type (refs #8338)

svn path=/trunk/boost/range/; revision=83596