add grain dist to scenario output

Created by: Lars Dalby

Imported comments:

By Lars Dalby on 2018-11-07T11:55:32.157Z

closed via commit 9eafa614

By Lars Dalby on 2018-11-07T11:55:32.157Z

closed via merge request !32

By Lars Dalby on 2018-11-07T11:54:42.743Z

mentioned in merge request !32