Big checkin, lots of fixes

From: David Abrahams (abrahams_at_[hidden])
Date: 2001-01-21 01:05:30

New Files:
  boost/detail/iterator.hpp
    Portable working versions of the following, in namespace detail:
      std::iterator_traits<>::iterator_category
      std::iterator_traits<>::difference_type
      std::distance()

  boost/libs/utility/iterator_traits_test.hpp
    Tests for the above

Modified:
  boost/array.hpp
    Added changelog

  boost/cast.hpp
    BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS to config.hpp.
    Removed unused BOOST_EXPLICIT_TARGET macro. 
    Moved boost::detail::type to boost/type.hpp.
    Made it compile with stock gcc again

  boost/config.hpp
    BOOST_NO_LIMITS_COMPILE_TIME_CONSTANTS moved here from cast.hpp.
    Added missing BOOST_NO_STRINGSTREAM which some boost code seemed to depend
    on.

  boost/detail/ob_type_traits.hpp
    Fixed is_same<T,U> so it would work with T == void or U == void
    Suppressed some warnings in from_not_void_conversion<> for MSVC
    Fixed a spelling error

  boost/python/operators.hpp
    A bug fix that I failed to check in long ago for the use of strstream

  libs/concept_check/class_concept_fail_expected.cpp
    Added warning suppression and changelog

  libs/conversion/test.hpp
    Fixed a warning for MSVC
    Added changelog

  libs/conversion/cast_test.cpp
    removed use of <limits> for portability to raw GCC
    
  libs/rational/rational_example.cpp
    Check BOOST_NO_LIMITS instead of __MINGW32__ where appropriate

  libs/utility/iterator_adaptors.htm
    A first attempt at clarifying the documentation for release

  status/compiler.cfg
    Turned on STLPort debug mode and turned off incremental linking
    for vc6 builds
    Added cygwin build
    Waiting for a fix for cygwin/stlport to add that

  status/regression.cfg
    Added iterator_traits_test.cpp