Better language detection and validation

[johannes85]

Correct me if i'm wrong but shouldn't the hl parameter in the cookie and request be validatet against the available locales ?

And i also extended the browser language detechtion by splitting the language from the country if both are set.

[schmittjoh]

Sounds good.

Could you please add tests, and also check the CS of your patch?

[johannes85]

At the moment i haven't the time i try to squeeze this in sometime.

[ajohnstone]

This should really be merged... Its very broken otherwise. I've started to fix a couple of the other unit tests, however a number more need to be fixed up.

[ASKozienko]

+1 but patch looks not so good :(