[RFC] use sigterm instead of sigkill to kill the server

sys.exit() causes a hang for some reason but
os._exit() does not

I'd rather know why sys.exit() hangs and has to be sigkilled of course. I didn't try very hard to find out but I thought others might have a clue. Hence, RFC.
fair enough, good point. I said the above because usually exceptions coming from a native layer tend to not be mapped very well into Python exceptions (at least this is the case when working with native code + JNI/Java, native exceptions are always a bitch to handle, and are in practice Runtime Exceptions that crash the app)

For this method in particular, what's very likely to happen, is that the router after lots of days running and lots of apps trying to map/clean maps might crap out and you won't be able to clean the mappings unless you restart it (happens quite a lot in the bittorrent world)