Addition to suppress the plots etc

[rengel8]

This PR is adding the ability to suppress the plots from showing, if the user only wants write them to disk. For the best genes the range on the y-axis can be used from the defined gene_space (if provided).

It might not be a perfect PR, but on updates I would again and again have to reimplement this. The variables/parameter can of cause get other names, but I still would like to be able to do something like shown by this..