changes since 5.x-1.4:
* updated the README
* #325618 patch by klausi: added a bunch of simpletests which make sure that the module is working right (with or without acl enabled)
* #325618: follow-up fix for the last fix - make sure re-creating ACL works. Furthermore fixed using priority for ACLs.
* #325618: when per node permissions are disabled for a content type, fix removing possible created per-user ACLs.
* improved the docs
* fixed implementation of hook_node_access_explain to return correct values
* fixed clearing the cache when permissions are updated