* Added DbCmd_PlaybackCharts - currently only supports artists, more to come.
Make track placeholder icon square
* Fixed qt picking wrong translations.
* Prevent crash in PlayableProxyModel.
* Style fixes for a few DbCmds.
* Mark-up tracks in the sidebar when hovered.
* Renamed trackCountChanged() to itemCountChanged() which is technically more correct.
* Changed various classes to use the new itemCountChanged() signal.
* Update control-states when queue changes.
Resulthintcheck
Revert "Resulthintcheck"

This reverts commit c5dd1ebf2fb6ed1113e4f2b35160c5edbc5a4069.
* Fixed safety-check in PlaylistInterface. 0 is a valid index.
* Implemented AlbumPlaylistInterface.
* Implemented ArtistPlaylistInterface.
* Only manually delete m_page in removeFromList().
Automatic merge of Transifex translations
* Moved prev/next check into PlaylistInterface.
* Prev/next check is now provided by PlaylistInterface.
* Correctly call PlaylistInterface's base-method in TreeProxyModelPlaylistInterface::setCurrentIndex.
* Check prev/next availability in Album- & ArtistPlaylistInterface.