Page routing and metadata

[jahndan]

Right now the dynamic routes accept any possible url

• [x] dynamic routes only accept valid subjects and ids
• [x] bare minimum metadata (title)
• [x] a 404 page should load when an invalid url is used
• [x] proper metadata generation

[jahndan]

I'm going to finish the dynamic routes stuff tonight (later we should look into proper metadata generation for all pages) — ideally someone else who knows better can make a nice looking 404 page and find out how to actually make it load when a nonexistent url is used

[chaunmt]

A simple 404 page is up. However, some components call for Access and pass by an invalid subject or id before calling the page --> Provoke an error message before provoke the 404 page. If anyone know their files are doing this, please fix it.