set correct position for unmanaged clients

- don't allow to move/resize with them
- don't focus unmanaged clients on buttonpress()

add support for layer_shell popups

use wlr_scene_xdg_surface_create() for xdg_popups

fix left border 'y' position

also add comment about border ordering

use wlr_scene_node_raise_to_top()

use wlr_scene_output_send_frame_done()

Merge branch 'scenegraph3' of github:djpohly/dwl into scenegraph3

Merge pull request #164 from Sevz17/change-border-color

Change border color according to focus state

Merge branch 'scenegraph3' of github:djpohly/dwl into scenegraph3

Merge pull request #151 from Sevz17/scenegraph3

send frame_done also to all layer surfaces

Merge branch 'main' into scenegraph3

Merge branch 'wlroots-next'

wlroots 0.15.0 was released

Merge branch 'main' of github:djpohly/dwl

Merge branch 'wlroots-next' into scenegraph3

explicitly create renderer and allocator

autocreate was removed

`wlr_xdg_surface.configure_serial` has been moved into `wlr_xdg_surface_state`

as seen in swaywm/wlroots@0e34208

Merge branch 'wlroots-next' of github:djpohly/dwl into wlroots-next

Merge commit 'refs/pull/162/head' of github:djpohly/dwl into scenegraph3

Merge branch 'wlroots-next' of github:djpohly/dwl into scenegraph3

change border color according to focus state