libsigc++: New API in libsigc++ 3.6

libsigc++ 3.8.0

New API in libsigc++ 3.6

Struct sigc::scoped_connection
Member sigc::signal_base::connect_first (const slot_base & slot_)
Member sigc::signal_base::connect_first (slot_base && slot_)
Member sigc::signal_with_accumulator< T_return, T_accumulator, T_arg >::connect_first (const slot_type & slot_)
Member sigc::signal_with_accumulator< T_return, T_accumulator, T_arg >::connect_first (slot_type && slot_)
Member sigc::trackable_signal_with_accumulator< T_return, T_accumulator, T_arg >::connect_first (const slot_type & slot_)
Member sigc::trackable_signal_with_accumulator< T_return, T_accumulator, T_arg >::connect_first (slot_type && slot_)