"<none>" option not working

Problem/Motivation

This module is blocking normal Drupal core permissions from being configured properly even when configured properly to allow that.

In the options for giving a certain role permissions based off of a taxonomy term selected, there is a "" option. That implies that if no term is selected in the field it will give that role access. This is perfect for allowing Drupal to allocate permissions on its own for the current roles while tac_lite is installed and used on other roles.

Steps to reproduce

1. Create two roles
2. Create two users for one of those roles each
3. Give one of those roles access to view and edit a specific content type
4. Via tac_lite, allow for the other role to need a specific taxonomy and the first role to have ""
5. Creating a new node and choosing no taxonomy related to tac_lite still restricts that content to be viewed and edited by the first role that should be allowed to default edit and view all from that content type

Proposed resolution

I believe this is an issue with `tac_lite_node_access_records()` hook. Whenever it can't find any terms selected, it just skips giving any role permissions.

Remaining tasks

User interface changes