Ability to add tabs to existing sets

[XFox111]

Feature request from a feedback:

One thing that would be great to have is the ability to add a tab into a particular group. I know that many times while working on a particular project, I'll think of a site that I need to look at or a search I need to do for another project when I get back to it. In Session Buddy you have the ability to save the new tab(s) and then merge them with the group they belong to.