DAR-307

- Created Special:Styleguide extension
- Extracted RenderContentOnlyHelper to be reused in both RenderContentOnly extension
  and Special:Styleguide
DAR-307

Added i18n file to the extension
DAR-307 Styleguide page

Moved all logic regarding rendering without typical Oasis alements
to BodyContentOnlyController.
Introduced levels of rendering
DAR-307

Added style to hide printfooter by default
DAR-307

Code review changes
DAR-307 Special:Styleguide

Fix for code being appended before doctype
DAR-307

Code review change
Merge branch 'DAR-307' into styleguide