[WIP] [DNM] Sonic grenades

In which Octobomb find new and interesting ways to break Travis, irritates @Nienhaus by asking for a sprite upload, frustrates Miauw with unreadable code, annoys Glloyd with placeholders tags and things in the wrong file and breaks everyone else's mind with the sheer unbalancedness that is liable to ensue. 
So, sonic grenades. 3 TC for a box of five grenades and syndicate earplugs, which not only are super effective against sonics also offer discrete protection from flashbangs too (child of earmuffs). The longest you'll be down for is 8 seconds (the tile or adjacent) and if that happens you'll stutter and won't be able to hear for 30s, which is the big advantage to yaketysax off as a syndie. It also shatters windows and windoors over a sizable radius. In short, needs nerfing. Hence the tags.
why leave the get_turf commented out?