[boost][date_time] errors in time_facet.hpp (cvs HEAD)

I think there are several errors in time_facet.hpp from cvs HEAD: The lines using std::basic_string::find() evaluate the return code wrongly, e.g. line 227: if (format.find(seconds_with_fractional_seconds_format)) { should be if (format.find(seconds_with_fractional_seconds_format) != string_type::npos) { I think. In addition I think "%%" should always evaluate to "%" and leave the following char unexpanded. Current e.g. "%%s" evaluates to "%59.000000", not to "%s". This is the outcome of using boost::algorithm::replace_all(). Otherwise thank you for your great library! Jan