Add swayc_change_layout function, which changes either layout or
workspace_layout, depending on the container type. Workspace being
always L_HORIZ makes this much more i3-compatible.
Focus the container on the output (not the output itself) when an output is
focused.
This is intended to fix a bug where borders are not updated correctly when
switching the vt away/back to sway.
When switching back to a workspace after new window creation, it is now
necessary to descend the focus stack into the focused container of the
workspace to determine which container should get the focus. This is because
the `set_focused_container()` function no longer automatically descends into
the focus stack to find the correct view to focus.
Replace `update_view_border()` with `update_container_border()`. The latter
should handle both the case where the container is a view or if the container
has children.
Panels were explicitly rendered by calling wlc_surface_render in
handle_output_pre_render. Calling wlc_surface_render does not set the
surface's geometry (like wlc_view_set_geometry does). Sway did not call
wlc_view_set_geometry for panels, so wlc defaulted their geometry to be at
the origin. This is not correct for bars unless their location is top.
Furthermore, for a surface to receive pointer events, its mask has to be
set to visible. This causes wlc to render these surfaces, causing panels
and backgrounds to be rendered twice.
This commit makes panels and surfaces visible, sets the correct geometries
and removes the code that explicitly rendered them.
Tabbed/stacked containers are now created only if a view is present on
the workspace. If a view is created on previously empty tabbed/stacked
workspace, it gets wrapped in a container.
Prior to this commit all windows (e.g. shell surfaces) were handled the same
way in handle_view_created. Since backgrounds and panels have to be treated
differently, they could not be shell surfaces. This changes checks whether
a client is a background or a panel in handle_view_created and exists to
let them be dealt with elsewhere.
