PG section reorder fix
fix the bug where reviewing a revision without a live revision breaks the world!
Merge branch 'feature/refactor-ug-pg-logic' of https://github.com/unikent/programmes-plant into refactor/menus-and-links

Conflicts:
	application/views/admin/inc/header.php
Merge branch 'refactor/menus-and-links' of github.com:unikent/programmes-plant into feature/refactor-ug-pg-logic