Kwplayer

* add classifiers
* Fixed: NoneType object is not iterable
* Press Shift+Delete keys to delete mp3 files from disk

* Put export worker to background thread
* Fixed: GstPlaybin(0.10) has no property `mute`
* Fixed: lrc text blinks on top of MV window
* Fixed: two songs might be deleted at a time by mistake when delete_button is clicked

* Support dark theme
* Get thumbnails one by one
* Fixed: ValueError: invalid literal for int() with base 10
* Fixed: check image is intact before loading; reported by wangjiezhe
* i18n updated

* Fixed: update icons in IconWindow
* Add timestamp to leveldb data
* Set background threads as daemon
* Using async_call to get artist list
* Automatically start caching daemon when song is added to cache list
* Single click to operate songs in songlist
* Fixed: Warning: Source ID xxx was not found when attempting to remove it

* Support PyGObject 3.11
* Redesign export dialog
* Fixed: active MTV button when playing MTV
* Show scale fill
* Simplify error message dialog
* Fixed: Invalid character in json string
* Lazy loading artist tab

* Add a favorite button to control panel
* Fixed: i18n KeyError; reported by MJsaka
* i18n updated