Added ability to filter by indigenous status on People Group index.
Created a private method for genrating a where statement based on a Boolean.  Refactored code to use it.
Added ability to filter by JPScale on People Group Index.  Also refactor code to remove validateContinents.
Added ability to filter by Least Reached on People Group Index.
Added ability to filter by unengaged on People Group Index.
Merge branch 'pg_index_statuses' into develop.  Added various status filters on the People Group Index.