4.8.5

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- Tasklist: Avoid unneeded dnd actions.
- Launcher: Fix plugin size with arrow button (bug #7747).
- Tasklist: Allow both motion activation and dnd (bug #7755).
- Panel: Fix off-by-one error in strut sizes (bug #7739).
- Tasklist: Fix assert in button dnd (bug #7741).
- Panel: Make preferences dialog work in Gtk+ 2.24.5.
- Systray: Add xfpm to known apps for a decent icon.
- Tasklist: Drop Gtk 2.22 API.
- Migrate: Fix 4.6 transparency migration (bug #7523).
- Translation updates (nl, zh_CN, de, pt, ja).