fixed error message during creation of groups
added a spec
refactors and by that applies html_safe to all blank_options
fixes error when retrieving a non-existant query
Adds missing tab select label
Removes superfluous variable
little alteration in spec test
found another prettier way
Removes layout table from work package index
made an update possible for the uniqueness validator
new version; updated changelog
Merge pull request #893 from opf/fix/missing_hidden_tab_selection_label_4109

[FIX] Missing hidden tab selection label 4109
Update CHANGELOG.md
Fixes page title
Adapts specs to authentication API rename
Renames authentication user id node
Merge pull request #889 from opf/fix/html_safe_missing_list_custom_fields

refactors and by that applies html_safe to all blank_options of a list custom field
added changelog
Merge pull request #892 from opf/fix/invalid_query_retrieval
Adds changelog entry