type moutain will make new terrain for you. You must put in a random
number after mountain at the command line. The source for the program
is in voxgen.cpp

Notes:
the first requested number controls the overall size of the terrain (1024 
would be really big)
the second controls the jumpiness of the terrain (numbers close
to 16384 are very jumpy)
the third contols the level of lighting on the terrain (small numbers
make very contrasted lighting, while large make smoother lighting)
the fourth controls how much to smooth the terrain (4 is extremely smooth,
0 is none). This can be used to counter jumpiness

the terrain in the program is generated with the number 432 to on the command
line, an then the following numbers sequentially in the program:
64
15000
5100
4