Debugging kdcs and signals

[Sam Hartman]

With the verfto merge, I find that when I'm debugging the KDC, I tend to
get interrupted by signals a lot more than I used to.

I'm not sure why, and at some level it would be nice if whatever was
being overly agressive about generating signals wouldn't.
However that's probably wishful thinking.

I would appreciate recommendations for debugging around this. I've
definitely found things go quite badly if I attempt to next through the
libev signal handler.