Refactor url handling

What does this MR do?

Refactor url handling to support xhtml files, pretty urls and avoid redirects.

Closes #156 (closed)
Closes #273 (closed)
Closes #418
Closes #9
Closes !259 (closed)

TODO

• Added the Changelog (e.g. Changelog: feature) trailer to the commits that need to be included in the changelog
• Added unit tests (if required)
• Added acceptance tests (if required)
• Documentation (if required)
• Code review guidelines
• Go Style guidelines