(PR#9610) autosettler "territory" and danger maps

<URL: http://bugs.freeciv.org/Ticket/Display.html?id=9610 >

> [jdorje - Sun Dec 19 18:22:07 2004]:
> You can't cast an int as a void* and treat it as a pointer.  This
> won't work on 64-bit systems

Widening isn't a problem (32-bit int to 64-bit pointer).  On all 64-bit systems I've heard of, 
int is no larger than void*.

Otherwise, we might want to have a "templated" list that can store arbitrary-sized structs, 
possibly using a genlist underneath and doing its own allocation.

And last thing: I haven't looked at the code closely, but it's possible that a specvec may work 
fine here; specvecs do their own allocation and thus obviate this problem.