Decouple the compose() function and the BOOST_PARAMETER_NO_SPEC_* code generation macros from BOOST_PARAMETER_MAX_ARITY for older compilers so their generated functions can take in more arguments.
* Add variadic metafunction boost::parameter::are_tagged_arguments to help improve overload resolution capabilities. Used by compose() and the new BOOST_PARAMETER_NO_SPEC_* code generation macros.
* Add variadic function template compose() which takes in named arguments and returns them in an argument pack.
* Add code generation macros BOOST_PARAMETER_BASIC_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_BASIC_CONST_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_FUNCTION, BOOST_PARAMETER_NO_SPEC_MEMBER_FUNCTION, BOOST_PARAMETER_NO_SPEC_CONST_MEMBER_FUNCTION, BOOST_PARAMETER_NO_SPEC_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_CONST_FUNCTION_CALL_OPERATOR, BOOST_PARAMETER_NO_SPEC_CONSTRUCTOR, and BOOST_PARAMETER_NO_SPEC_NO_BASE_CONSTRUCTOR.
