Associate thumbnail request with widget pointers, so that we can hook into ThunarIconFactory and ThunarThumbnailer from ThunarIconRenderer in order to cancel requests from ThunarStandardView (and others) when the active directory changes.
Query supported URI schemes and MIME types from the thumbnailer service asynchronously to make Thunar start up faster.
Improve the responsiveness of the file operations dialog (once again evaluate the tricks introduced to keep CPU usage low when a lot of signals are emitted).
Try to figure out what's wrong with remote volume monitors (e.g. SMB, SFTP).