Move getting tags/archives to methods in Blog class. Tried to
cache but couldn't get it to work.
Add a categories view which either lists categories or shows
blog posts filtered by the provided tag (kinda hacky)
Reworked pagination so it works via URL's like
blog/categories/tag1/{page-number} or
blog/view/{page-number}

It's a bit hacky and I couldn't make it work with
blog/{page-number} though ...
Make sure to use the new categories URL's everywhere
Implemented archives in the same way as categories (will fix
comments later, need sleep now o.O)
New archives URL in sidebar
Fix archives and categories "list" view
(note: ''.split('/') is not an empty list ... :P)
Use archives template on archives listing, fixes to the
archives template
Use correct url's in archives listing