Various new features

I've been playing with this for the past few days and have done some cleaning up of the code and implemented some new features I thought might be beneficial to others

* Specify display name, admin url for a site
* Hide sites from the list
* Create custom links for use in top navigation bar
* Specify additional prefered icons to show

If you don't want all of this or just want a specific feature I would be happy to pull it out and create a separate pull request - just let me know.