Bump to 3.9.91
added attach option for transient window
Updated Slovenian translation
Updated Galician translations
Updated Greek translation
Updated Polish translation
Updated Brazilian Portuguese translation
Updated Lithuanian translation
Updated Spanish translation
Updated Hebrew translation.
[l10n] Updated Italian translation.
Update French translation
Updated Hungarian translation
Updated Czech translation
Updated Czech translation
Updated Serbian translation
Updated Traditional Chinese translation(Hong Kong and Taiwan)
Updated Russian translation
Updated German translation
Updated Norwegian bokmål translation