[boost] [string_algo] A tiny bug in the first trimming example.

Hi. There seems to be a bug in the first trimming example for the string_algo library. (link: http://www.boost.org/doc/html/string_algo/usage.html#id576378) My guess is the line: string str3=trim_right_copy(str2) was meant to be: string str3=trim_right_copy(str1) or otherwise the comment beside it is incorrect. Hope this helps, Jurko Gospodnetiæ