Lots of view love. Fixes ndlib/planning#263

This tries to do a bunch of things:
- Hide results when displaying a blank search
- Link site title to root path
- Flexing the search layout to accommodate welcome screen
- "Home" page allows discovery; fixes ndlib/planning#263.
- Updating the search results views
- Reordering search result actions
- Site title color adjustments
- Datasets have descriptions not abstracts
- Tidying up attribute listings