Ports Baystation12/Baystation12#19992 and Baystation12/Baystation12#27266.
Added a personal shield device to the traitor tools uplink.
Added a radiant shielding aura spell to Battlemage and Cleric.
Added an exosuit shield drone to the mechfab.
This works, but I'm not entirely happy with the sprites. The personal shield has no on-mob shimmer, it uses a mindbatterer grenade as an icon sprite. The wizard radiant spell uses a pretty big and janky sprite as an on-mob, and the exosuit's shield sprite doesn't follow the dir the mech faces, but that one I can maybe fix on my own. If anyone knows about that last one, lemme know, Bay had code for it that we do not.
