improve new SPV

* Hopefully fix OEmbed view
* Fix OpenGraph view
* Fix middle border
* Add spacing at the bottom
* Fix comment styles by not including old SPV styles for them (TODO: maybe rescue some stuff there, like the code tag styling)
* Fix avatar size for default avatar
* Remove border below comment pane
* Fix overflow of post body with a lot of text
* Fix stylesheet inclusion
Merge pull request #1 from MrZYX/rogerbraun-feature/spv-redesign

SPV fixes