Configure login capabilities on FreeBSD

Summary:
The default login class is 'english' and can be overrided by
expression like 'class: french' in users pillar.

The classes provide UTF-8 charset and language-based local.

Test Plan: Test on WindRiver

Reviewers: dereckson

Reviewed By: dereckson

Differential Revision: https://devcentral.nasqueron.org/D2135