Only export badge titles in proposal votedetail export

Previously the whole badge dict together with a complete list of users
was exported redundantly for each proposal.
fix comment form cancel (fixes #498)
[scss] fix table.line_based
rm "Zwischenüberschrift" and mv "edit" to header
Merge pull request #508 from xi/feature-rm-proposal-topic+

rm "Zwischenüberschrift" and mv "edit" to header
Merge pull request #507 from xi/feature-fix-comment-form-cancel

fix comment form cancel
Allow to rename "Overview to Intro"