Swedish (sv)

Translated the remaining strings to Swedish.

Not sure what the convention is regarding encoding / non-english characters. For now, I simply mimicked the already translated strings and used HTML entities when necessary. (`&aring; (å)` `&auml; (ä)` `&ouml; (ö)`)

It might be better to agree on an encoding (UTF-8) and stick with that. If so, it should probably be mentioned in the readme.