The Browncoat Update - Handle FireEchoSound using a scene area

[pawnishoovy]

FireEchoSound is basically FireSound2 right now, but it can be turned into something really useful relatively easily without any complicated systems

1. Scenes place an area called "Indoor Area", which is hardcoded to be kept track of through C++.
2. Any guns firing inside that area do not play their FireEchoSound.
3. Any guns firing outside that area do play their FireEchoSound.

This doesn't handle radically changing the map in gameplay, but that can be for much later. This would still be accurate in 90% of scenarios give or take, assuming nobody uses Thomas The Thermonuclear Engine (but if their guns act wonky after that, it's their own damn fault)