Add possiblity to set the crate probability of the super weapons
It would be nice to set the crate pobability of the super weapons because some of them can be good to find in a crate for a scheme, but others should never appear (armageddon for exemple in many cases). This should be possible without breaking RubberWorm's schemes.
I believe this is in the works for 3.×. The scheme version number will probably be increased to avoid RubberWorm incompatibility issues.