[Simh] sigma simulator

[Mark Pizzolato - Info Comm]

On Wednesday, July 2, 2014 at 10:49 AM, Cory Smelosky wrote:
> Hello,
> 
> The unfinished sigma simulator dumps core on quit...which I find interesting.
> Will look in to finding out /why/.
> 
> Not that the simulator really works otherwise, mind...;)

Fixed now.  

Also added makefile sections and Visual Studio Projects for sigma and alpha.  Sigma and alpha aren't built unless they are explicitly mentioned on the make command line (they are not included in 'all' since they aren't finished).  These are provided in case someone wants to work towards completing them.

- Mark