Lataa Thorium 2.2.0

This release includes the following (notable) new features, improvements and bug fixes:
- Updated translations: English, Simplified Chinese, Traditional Chinese, Italian, Japanese, Lithuanian, Spanish, Swedish
- Now with Electron 21 (more recent Chromium web browser engine)
- Feature: show accessibility metadata in publication info dialog
- Fix: MathML support via MathJax, screen reader interaction (accessibility)
- Feature: navigation history, back / forward buttons with keyboard shortcuts
- Fix: TTS and Media Overlays playback options were reset to default values in GUI but not in backend
- Fix: EPUB FXL Fixed-Layout pre-paginated publications can now render with single centered pages (override from authored spread rules, when aspect ratio is portrait instead of landscape)
- Feature: EPUB FXL Fixed-Layout zoom now with keyboard shorcuts (increase, decrease and reset)
- Fix: EPUB FXL and reflowable, support for pagebreak and pagelist edge cases, improved "goto page" navigation
- Fix: support for self-closing body HTML tag in document parser
- Fix: keyboard focus returns to popup menu callsite after cancel-closing publication delete modal dialog (improves usability and accessibility with screen readers)
- Fix: improved popup modal dialog GUI, better default enter key behaviour and form submission behaviour
- Fix: improved CSS styling in reader menu, removed non-implemented annotation menu (future feature)
- Fix: OPDS HTTP basic authentication now handles 302 "found" redirection for GET requests
- Fix: OPDS indirect acquisitions can have child subtype, now display EPUB/PDF and LCP info in download buttons (after generic authenticated borrow action)
- Feature: OPDS edit feed title and url
- Fix: tag name with special characters now supported
- Fix: DAISY v2.02 HTML NCC metadata parsing, multimedia type full text audio is default
- Feature: OPDS HTTP digest authentication scheme, supports Calibre content server
- Fix: multilingual metadata parsing (title, author, etc.), RTL for Hebrew, Arabic, etc. now displayed correctly
- Fix: URL protocol/scheme handlers thorium:// and opds:// work on Mac Linux and Windows
- Fix: MacOS 'window' menu in top-level instead of submenu
- Fix: accessible screen reader label for secondary navigation landmark in bookshelf is just "menu" to avoid duplication of announcement
- Fix: added application keywords for Linux integration
- Fix: clearer error reporting when opening a file with unsupported extension (derived from HTTP content-type or obtained from filesystem)
- Fix: Mac and Linux application icons
- Fix: cancelling one download only now works
- Fix: publication info, list of authors now complete
- Fix: OPDS, support for DAISY application/zip mimetype