meta_window: Allow to set skip_taskbar property
This patch adds two new methods: meta_window_skip_from_taskbar() and meta_window_show_in_taskbar(), that allows to enable and disable the skip_taskbar in a MetaWindow.
With these methods, an extension can hide a window from the list of windows. Under X11 this is not needed, but under Wayland there isn't another way. It is complemented by !754 (merged), which allows to detect, in a secure way, if a window belows to a process launched from an extension, thus ensuring that only the specific process launched from the extension receives this privilege.
Fixes: #733 (closed)
Edited by Rastersoft