Consider merging the breadcrumbs + navbar

[joepio]

We now have two bars shown, which has some problems:

• Lots of space used
• Two places where users can navigate
• Pressing scoped search button requires user to look at the other bar, which is confusing

I think we can merge both into one single bar by doing this:

• Get rid of the current URL. It's not necessarily useful in browser context
• Get rid of the big search text
• Use only one search button / icon
• Move hierarchy info to where the search bar / url bar now is