Problem with the sfCoreAutoload and Locales like turkish

[sbeining]

I ran into a problem when using sf_culture in a route.

The route was called with "tr_TR" and that caused error that the sfServiceContainerInterface could not be found.

The problem is that the sf_culture is parsed and set as the locale. This locale will be used for functions like strtolower and the result can differ depending on the locale.

I submitted a pull request with a fix: #206