BUGFIX
Always remove duplicates from tags, not only when a tag is set in the indexer configuration. github.com/tpwd/ke_search/issues/211
Fix TypeError after 'RemoveLock'. Thanks to Stephan Bauer. github.com/tpwd/ke_search/issues/223
Avoid PHP warning "Undefined array key" in TimeUtility. github.com/tpwd/ke_search/issues/221