[Crash-utility] sig -g and foreach sig -g

[Dave Anderson]

> May be there is a difficulty with free_all_bufs() ?
> If i understand well the foreach() function :

Hi Olivier,

As it turns out, the "foreach sig -g" can be accomplished in a much easier
manner by using crash's built-in hq_xxx() hash queue functionality.

So there's no need to (1) pre-allocate anything, or (2) re-invent the wheel
by creating a new hashing function.

Anyway, I've got the "foreach sig -g" piece pretty much complete -- so
I'll take it from here.

Thanks again for your contribution,
  Dave