[bug 859973] Improve Groups Listing view

I haven't added sorting options yet. Current sorting is done alphabetically using name of the groups. I'll add that soon, once I figure out how to use the members count as the "order_by" criteria.

Current screen looks like this:

![screenshot - thursday 23 may 2013 - 03 53 51 ist](https://f.cloud.github.com/assets/364832/551610/8aaaa068-c32e-11e2-97ec-1be00fc1d5a3.png)