Revert "Removed superfluous Pages, using @pagetitle instead"

Adding view code to controllers was a bad idea™

This reverts commit 06ebc5368491229825e7ba7e967ec80716ffc93e.
Add and use special attribute (for pages like /shows /archive etc)
Add attribute :is_secondary (bool) for pages that don't need to be displayed in main nav
Add attribute is_unimportant
add attribute is_hidden to pages (used for 404 for example)
Use new cool attributes