Substitute boost::is_lvalue_reference with partial template specialisation.
Substitute boost::is_lvalue_reference with partial template specialisation.

This avoids a dependency on Boost ≥ 1.44.0.

Use the existing implementation of is_nonconst_reference for compilers
that do not support partial template specialisation, as we can assume
that the same compilers do not support rvalue references.

Conflicts:
	luabind/detail/typetraits.hpp

Oberon00/luabind,Oberon00/luabind,lonski/luabind