[boost] [utility][enable_if] Documentation issue

The documentation for `enable_if` has a duplicated anchor for sections 3.1 and 3.2, making it impossible to link to section 3.2 directly. See http://www.boost.org/libs/utility/enable_if.html#htoc7 This issue is still present in trunk. Could this be fixed? I could provide a patch but I do not see a .qbk file for it, should the html be modified directly? Regards, -- Agustín K-ballo Bergé.- http://talesofcpp.fusionfenix.com