core: call_tree
core: call_tree

- add_new_link_if_missing function removed
- action_set_t::NO_ACTION is used to represent non-valid action in root
- sanity check for action_code validity in add_new_link

tempbottle/react-1,reverbrain/react,tempbottle/react-1,tempbottle/react-1,tempbottle/react-1,reverbrain/react,reverbrain/react