ENH: update dependencies to Boost v1.49.0

Utilities/BGL/boost/math/common_factor_ct.hpp

Utilities/BGL/boost/mpl/equal.hpp

Utilities/BGL/boost/mpl/max_element.hpp

Utilities/BGL/boost/variant.hpp

Utilities/BGL/boost/variant/apply_visitor.hpp

Utilities/BGL/boost/variant/bad_visit.hpp

Utilities/BGL/boost/variant/detail/apply_visitor_binary.hpp

Utilities/BGL/boost/variant/detail/apply_visitor_delayed.hpp

Utilities/BGL/boost/variant/detail/apply_visitor_unary.hpp

Utilities/BGL/boost/variant/detail/backup_holder.hpp

Utilities/BGL/boost/variant/detail/bool_trait_def.hpp

Utilities/BGL/boost/variant/detail/bool_trait_undef.hpp

Utilities/BGL/boost/variant/detail/cast_storage.hpp

Utilities/BGL/boost/variant/detail/config.hpp

Utilities/BGL/boost/variant/detail/enable_recursive.hpp

Utilities/BGL/boost/variant/detail/enable_recursive_fwd.hpp

Utilities/BGL/boost/variant/detail/forced_return.hpp

Utilities/BGL/boost/variant/detail/generic_result_type.hpp

Utilities/BGL/boost/variant/detail/has_nothrow_move.hpp

Utilities/BGL/boost/variant/detail/has_trivial_move.hpp