Adds a new FRAG-12 explosive shotgun shell

Adds FRAG-12 shotgun shells as a new type of shell built from the unloaded technological shell. Does 45 brute damage and 5 weaken, additionally causing a (-1, -1, 1) explosion over the target. In testing, the shell always caused 69 brute damage to a human target, spread across multiple body parts. Current recipe uses table crafting, and requires an unloaded techshell, and five units each of glycerol, sulphuric acid and polytrinic acid, the same recipe as nitroglycerine.
Additionally, adding myself to admins.txt.
You'll want to set this as usually only maintainers have a permanent one, just remove the # to make the line active