Refactoring of page template handling
- Easier to select the kind of page (nav, no nav, popup)
- All menu entries are now easier to mark active (page_type block replaced by page_nav)
- Unified no-nav-page template
- Messages display block width now depends on where it is used
- Error page now styled
Merge pull request #1561 from rarila/page-extends

Refactoring of page template handling