Add Swedish translation

This translation will be updated whenever the project is compiled. Small issues will then be pull requested and fixed. I'll also make sure to get a friend to proof read this, lowering the risk of initial problems. A comment will be posted when this has been done.

Since you are the project leader it is up to you to decide if you want this translation to be added. All I can do is to help with the work and tell you that some people actually will use this, just not very many.