Rename 'Public User Pages and Listings' Profile Visibility option to 'Public Pages with Links', remove it from Groups Visibility options (not used)

As noted in the forum post below, the "label" is confusing for the Profile field visibility option which allows users to "link" from viewing one contact to a list of others with the same value (currently "Public User Pages and Listings"). Also, as far as I can tell, this visibility option is not actually used / needed for Groups - although included in the column enum and the group settings from (civicrm_group.visiblity).

1. Verify that for GROUPS the "Public User Pages and Listings" option is not needed (i.e. no different behaviors from "Public User Pages").

2. Modify the visiblity column in civicrm_uf_group - changing the 2nd value to "Public Pages", and the 3rd value to "Public Pages and Listings"

3. Modify the visiblity column in civicrm_group - changing the 2nd value to "Public Pages", and removing the 3rd value

4. Modify /Core/SelectValues.php to return the 3 valid options for Profile Group and the 2 valid options for Group.

5. Fix the php classes to use the new visibility string value.

6. Review and modify any .hlp or inline help for these forms to correct the labels referenced, and remove the extra visibility option from the descriptions.