Changes to biogenerator code + small bugfix

1.This changes the biogenerator code a bit so its a bit better and easier to add new stuff to it. It also fixes a small bug where you would only get 3 nutrient bottles instead of 5 when using the x5 option.

2.This fixes juggernauts and other simple animals which can destroy stuff not being able to destroy metal foam walls.
Fixes #4070