fix signal_changed emitted by property::link on cereal load.
fix bug in link_mixin::decompose_numeric_timeserie().
use pointer instead of const_pointer to hold property nodes.
move model::config::add_robot to model::config::Root, same for model::config::robot::add_sensor.
Derive from enable_shared_from_this at property::node_base.
fix wrong type in signal slot.
integrate AntTweakar.