ticket:272 setted tabindexes
ticket:272 fixed merge conflict in base.html
ticket:273 titles to help pages
ticket:273 fix headers
ticket:272 open filters ddcl on click enter
Merge branch 't272_filters_should_be_selectable_by_keyboard' into accessibility
Merge branch 'accessibility' into t273_some_pages_have_same_title
ticket:273 added added titles for all help pages, cart and error pages
Merge branch 't273_some_pages_have_same_title' into accessibility