Swedish translation

[Centril]

Adds Swedish translations of everything except for faq.md (too long... didn't have time).

r? @steveklabnik
cc @bluss

[rust-highfive]

Thanks for the pull request, and welcome! The Rust team is excited to review your changes, and you should hear from @steveklabnik (or someone else) soon.

If any changes to this PR are deemed necessary, please add them as extra commits. This ensures that the reviewer can see what has changed since they last reviewed the code. Due to the way GitHub handles out-of-date commits, this should also make it reasonably obvious what issues have or haven't been addressed. Large or tricky changes may require several passes of review and changes.

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[steveklabnik]

This is very amusing, I am actually in Malmö at the moment!

I'm going to leave this open for a bit so that other interested people can review, happy to merge after a while.

[Centril]

@steveklabnik I know right!

cc some Swedish speakers @faern, @fkaa, @udoprog