Adds claim response button to adminhelps

Adds claim response button to adminhelps which will hopefully mean there aren't three admins PMing the same guy at once.

Messages but doesn't log since it's only meant for the benefit of admins online and I can't imagine how seeing who claimed an adminhelp would be useful, but this can easily be added.

Polling if people want this added to prayers as well since no-one responded in the bus :'(
http://tgstation13.org/phpBB/viewtopic.php?f=29&t=1321

Also gunnary > gunnery spellfix