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 .
In this project this kind of variable name is not used.
m_ctx consists of 'm_' prefix and 'ctx' (a short of context).
And some lines uses g_ prefix for the (locally) global variable.
So how about using 'g_deleteActionCtx'.