Improving localization

I'm new to RoR thus I'm sorry if my code is not very good.
Also I didn't managed to run test. I report about my problem to google groups but with no response. https://groups.google.com/forum/?fromgroups#!topic/communityengine/i3Plt5m-6Vk

What was changed:
1. Added  check that supported local exists. Before changes it failed when locale=en-US.
2. Added ability to switch locale by choosing domain.
3. Added hyperlinks at the top of the page to switch language

Hope it will be usefull