do_after progress bars (#1857)

Adds the do_after progress bars that were originally going to be added with lighting, but got scrapped due to PR-bloat.

changes:

do_after actions now have a progress bar.
Added a changelog for directional lighting as I apparently forgot it.
The do_after proc's required arguments are unchanged, however it now accepts the argument act_target, which allows the caller to specify what object the progress bar should appear over. Defaults to user.

code/ATMOSPHERICS/components/binary_devices/passive_gate.dm

@@ -250,7 +250,7 @@
 		return 1
 	playsound(src.loc, 'sound/items/Ratchet.ogg', 50, 1)
 	user << "<span class='notice'>You begin to unfasten \the [src]...</span>"
-	if (do_after(user, 40))
+	if (do_after(user, 40, act_target = src))
 		user.visible_message( \
 			"<span class='notice'>\The [user] unfastens \the [src].</span>", \
 			"<span class='notice'>You have unfastened \the [src].</span>", \

code/ATMOSPHERICS/components/binary_devices/pump.dm

@@ -229,7 +229,7 @@ Thus, the two variables affect pump operation are set in New():
 		return 1
 	playsound(src.loc, 'sound/items/Ratchet.ogg', 50, 1)
 	user << "<span class='notice'>You begin to unfasten \the [src]...</span>"
-	if (do_after(user, 40))
+	if (do_after(user, 40, act_target = src))
 		user.visible_message( \
 			"<span class='notice'>\The [user] unfastens \the [src].</span>", \
 			"<span class='notice'>You have unfastened \the [src].</span>", \