char_traits.h (class char_traits): Put all the real work into the new class template __gnu_cxx::char_traits.


	* /include/bits/char_traits.h (class char_traits): Put all the
	real work into the new class template __gnu_cxx::char_traits.
	Gave generic definitions for member functions.  Types are taken
	from the new class template __gnu_cxx::_Char_types.
	* testsuite/21_strings/char_traits/requirements/short/1.cc: New
	file.  Test of std::char_traits<short>, which serves as a test of
	the char_traits primary template.

From-SVN: r69772