This adds throw_alert() and /obj/screen/alert, a system that allows you to do custom hud alerts for any variety of things from "You're too cold!" to mecha status indicators for the pilot.
There's quite a few things that actually got replaced; the
fire/oxy/tox/co2 alerts are all now just alerts, as is nutrition. There's also a number of new alerts, such as blindness, highness, legcuffed, buckled, handcuffed, and probably some more I missed; read code/_onclick/hud/alert.dm and see for yourself!
Additionally, a number of tweaks have been done to resisting code, to make it so that there's an indicator when you're buckled or handcuffed, and can just click the alert to start resisting. This includes a refactor that combines the logic for lockers, holders all into one proc, called container_resist().
Also, the health and internals indicator got moved down one tile each. Needed room for the alerts. If we add the oxygen tank action buttons from /tg/ and remove the internals indicator, the health indicator can go back where it was originally.
Alerts, pictured in the top right.

* Fixes Runtime in tools.dm,239: undefined variable /mob/living/simple_animal/retaliate/solargrub/var/handcuffed
* Add logging to help identify the cause of runtime in examining zshadow mobs.
* Fix Runtime in buckling.dm,165: Cannot execute null.forceMove().
* Fixes Runtime in robot_items.dm,31: Cannot read null.origin_tech
* Fixes Runtime in paper_bundle.dm,183: Cannot read null.loc
Mobs now have the ability to "crawl" to an adjacent turf by click-dragging themselves to it. This would allow people unable to stand to still move around, though very slowly. You could also do this to other movable mobs or objects, if you really wanted to.
Moving this way takes about 2.5 seconds, plus half a second for each point of weakness you have. For a person missing a leg, this would take 5 seconds. It only works if the mob doing this is alive, conscious, unrestrained, not stunned or paralyzed, and in an area with gravity - no crawling through space.
Mobs lying on the ground - again, with similar restrictions - are now able to buckle themselves to chairs or beds. For people missing legs or feet, this means no more being stuck helpless on the ground forever because Baldie McGreytide clicked on your wheelchair.
Tested in many different situations, and I've patched every bug that popped up.
Checks if what they're attacking 'bare-handed' is adjacent to the cyborg, and has something buckled to it. If not, it passes the click on to AI click like usual.
Buckling procs and vars have been moved down to /obj.
Behaviour is mostly the same, but you can buckle cuffed people to
pipes and they will automatically unbuckle if the cuffs are removed.
Signed-off-by: Mloc-Argent <colmohici@gmail.com>