Update the fixtures

Now there are two galleries with one category each.
Remove the gap between menus

Looks better without it.
Fix associations on Category

Let it know that it has many Products.
Update public views for Galleries

Tweak the routes and controllers. Implement the core functionality —
the menu and navigating through everything.
Fix the layout

There were some inconsistencies. It’s probably better now, but still
not perfect.
Create static pages for the frontend

I’m using a separate controller for each one of them, which might seem
redundant, but is quite elegant in terms of resources/routes.
Fix links in the top menu

Works well, but active_link_to has some limitations that should be felt
with.