UX tweaks and translations

helios/forms.py

helios/media/static_templates/question.html

helios/templates/election_view.html

helios/templates/elections_administered.html

helios/templates/elections_voted.html

helios/templates/email/info_body.txt

helios/templates/email/result_body.txt

helios/templates/email/simple_body.txt

helios/templates/email/vote_body.txt

helios/templates/list_trustees.html

heliosbooth/templates/question.html

server_ui/templates/index.html