Remove use of obsolete BOOST_APPEND_EXPLICIT_TEMPLATE_TYPE{,_SPEC} macro.
Utility: Remove obsolete MSVC version check
Remove obsolete MSVC check from pragma guard

 git grep -h -B1 "^#\s*pragma once" | grep -v pragma | sort | uniq

is now clean.
Ref: Remove obsolete MSVC version check.
Detail: Remove obsolete MSVC version checks.
Remove check for obsolete DMC version.
Operators: Remove obsolete GCC version check.
Fix #9169 - Add BOOST_FORCEINLINE on boost::ref for performance issue
Fix #9170 - Add BOOST_FORCEINLINE in address_of for performance issues