BP Access Controll Plugin:

A) _bpac_visible_for
	1) all
	2) specific_groups
	3) specific_users

B) _bpac_users_of_group_have_access

C) _bpac_user_has_access


visible for	map to		DB
------------	------		---
all		none		A=>1
all		group		A=>1, B=>group_ids
specific group	group		A=>2, B=>group_ids, C=>user_ids
specific user	user		A=>3, C=>user_ids