merge PR #959
add new flags (burkina faso + madagascar)
Update admin_ui.es.yml #960
exporting empty belong_to field does not break the whole csv
Merge branch 'v2.5.x' into 2houses

Conflicts:
	app/controllers/locomotive/api/base_controller.rb
	app/views/locomotive/public/sitemaps/show.xml.builder
	config/locales/admin_ui.fr.yml
	lib/locomotive/configuration.rb
	lib/locomotive/liquid/tags/path_helper.rb