Geiger counters now have sounds, which I took from https://freesound.org/people/leonelmail/sounds/328381/ and chopped it up into several .oggs. The license is CC0 (public domain) so it'll fit with our license.
The Geiger counter now turns yellow at any sign of radiation instead of at 5 units, since below five units is still harmful.
Examining the Geiger counter updates the radiation count immediately.
* The performance of the radiation controller as-is was not fast enough for inclusion in production servers, but it has some nice featuers, so rewrote it to be more performant.
* Instead of storing the radiation strength for every turf, we only store the sources of radiation, and calculate the strength only for mobs who might be in range.
* Old method was ray-tracing to every turf in range whether anything was there to be irradiated or not. Could be hundreds of turfs. New method only lazily calcualtes strength at a turf if we actually need to know it. Often times this is zero turfs if nobody is standing in engineering.
* Removed the automatic processing of objects with "rad_power" set. Objects are responsible for calling the repository to create/update their radiation sources. Saves some extra overhead that in practice was redundant with other process controllers.
* Also tweaked to be more respectful of qdel'd objects and added some comments.
