Syndicate shotguns to replace the eguns

Shotguns:
- Initially loaded with taser slugs
- Extra ammo is pretty economical from the uplink
- Replace boring eguns, makes nuke ops more ballistic-focused
- Leave trails of spent shotgun shells whereever you go

Other changes:
- Tweaked some descriptions
- Tweaked some file path names for shotgun ammos
- Tweaked some names

Pics later
Sprites by ausops
If you're not actually using the vars in the parenthesis in the particular proc, you don't need them. They're for passing information from one proc to another, but the only thing this proc is acting upon is src (the gun itself, which is known by default).

 They don't seem to be getting used here, so this line should end with proc/empty_alarm()
 with no parameters in ()