Nested groups.

First of all, I would like to thank the author for such useful software. It seems to me that this is currently the best free SSH\Shell\SFTP client I've ever seen. I would like to propose a few of new features, and the first of these will be nested groups.

I think that unlimited nesting of groups will allow more correct organization of sessions for those who have a lot of them. I have many sessions and most of them should be grouped into different data centers, zones, clusters, etc.