Fixes `hide_edge_borders smart` when gaps are in use.
Implements `hide_edge_borders smart_no_gaps` and `smart_borders
on|no_gaps|off`.
Since `smart_borders on` is equivalent to `hide_edge_borders smart`
and `smart_borders no_gaps` is equivalent to `hide_edge_borders
smart_no_gaps`, I opted to just save the last value set for
`hide_edge_borders` and restore that on `smart_borders off`. This
simplifies the conditions for setting the border.
This allows for a color to be set when the wallpaper does not fill the
entire output. If specified, the fallback color is also used when the
image path is inaccessible.
Adds the --locked flag to bindsym and bindcode commands.
When a keyboard's associated seat has an exclusive client
(i.e, a screenlocker), then bindings are only executed if
they have the locked flag. When there is no such client,
this restriction is lifted.