change int_type in std::char_traits<cxxtools::Char> to int64_t
change int_type in std::char_traits<cxxtools::Char> to int64_t

Now we can guaratee, that the int_type is larger that value_type of cxxtools::Char
which is necessary for eof value.

maekitalo/cxxtools,maekitalo/cxxtools,maekitalo/cxxtools,maekitalo/cxxtools