Neos UI hierarchy

Tweaking the top-level hierarchy and visuals to make it easier to distinguish different panels and types of content. There is a lot of functionality in this UI for creating and editing pages and content, so it's a real challenge to find a simple mental & UI model for various types of users and still allowing complex interactions. The iterative, community-driven nature of this open-source project really lends itself to quickly working through different ideas, which is great.