[x] Landing page looks bad at startup, currently shows an empty Detail View, and even sessions is ugly. Figure out a good idiom for the default page. See #131
[x] Buttons for actions like "Add Host", "Add Key" take a lot of space, and the layout is not optimal. Put a max size, and when we have multiple, maybe use a different tool than a List
[x] Host listing, Key listing, Known Host listing look horrible as List items with a lot of space, perhaps we need cells and a different layout for them.
[x] Empty pages (Hosts, Keys) probably could use a graphic/text explaining the purpose of a page.
This is a follow up to #7 and #55
General issues: