issue #107, Remove the Action of without owner.

When remove the "User", to remove the "access_list" together, but don't remove "actions". 
When displaying the "actions", to display only the "actions" that the user(owner) is exists. 
To delete the "actions", run the deletion process on a cyclic(example:3600sec(1h)), 
to remove an "actions" if there is no owner user.However, USER_ID_SYSTEM is excluded .
> ACTION_DELETE_DEFAULT_INTERVAL

BTW the place of "DEFAULT" seems unnatural for me.
I prefer put it to head or tail, or remove it.

DEFAULT_ACTION_DELETE_INTERVAL
ACTION_DELETE_INTERVAL_DEFAULT
ACTION_DELETE_INTERVAL