Make newcap's second argument mandatory

Make newcap's second argument mandatory

The code to find a suitable sanctuary location is flawed: to find
space and resources around the location, it does a depth-first search
limited to 300 sectors.  Pretty useless when the limit is reached.  A
breadth-first search would work, but why bother?  This feature is
obscure and rarely (if ever) used: no conscientious deity would use it
for a real game, and for blitzes fairland does a better job.  Remove
it.