Added Locale Service. Minor Controller Refactoring.

Hi there!

I started extracting some "buisiness" logic into a seperate provider/service. My goal, also in preparation for angular 2.0 some day, is to have as much of non binding logic to fit in services. So the migration won't be to much of a pain one day.

I started with this small chunk because it was just easy to extract. So that the monster SyncthingController can shrink in size over time.

Regards,
Dennis
I am not sure what to do with this now. So if it is ok for you, I would like to leave the locale matching to you for now.