Mir Lands Server-Side Decoration Support For XWayland

Making Mir's XWayland support much more usable now is initial server-side decoration support in order to handle window resizing and window movements.

Mir's XWayland support to date hasn't supported server-side decorations and thus losing out not only on window decorations but functionality like window resizing and movements. Now in the newest Mir development code is this SSD support wired up.

The Canonical developers involved are looking at extending this server-side decoration functionality in the future should any Mir shells want to provide their own SSD implementation and supporting the Wayland protocols for requesting server-side decorations.

Aside from server-side decorations, they are planning other Mir XWayland improvements as well "until XWayland in Mir is fully usable" and near parity with the native Wayland client handling.

More details on Ubuntu.com and adding to the Mir accomplishments of 2019.