netbus.c: fix memory leak
cert.c: fix memory leak
add function to destroy passport and node_info object
udt: update udtbus_server API to return peer_t object
so it can be freed easily
netbus: fix memory leak
update net_server API to return netc_t object, this
way it can be freed easily
mbuf: change the name of the free callback pointer
dnd/session: fix memory leak, free node_info
dnd/context: add context_free function, flush every context
update linkst field
dnd/dsc: set pthread detached
add fini mechanism
dnd/dnd: set pthread detached
add fini mechanism
dnd/main: catch signal and call fini
dnd: code cleanup