Patch tested by compiling with `__attribute__ ((format (printf, 2, 3)))`
applied to `cmd_results_new`.
String usage constants have been converted from pointers to arrays when
encountered. General handler format strings were sometimes modified to
include the old input string, especially for unknown command errors.
The directive sets the timeout before an urgent view becomes normal
again after switching to it from another workspace.
Also:
* When an xwayland surface removes the urgent hint while the timer is
active, we now ignore the request. This happens as soon as the view
receives focus, so it was effectively making the timer pointless.
* The timeout is now only applied when switching to it from another
workspace.
