Force lowercase method names for PHP up to 5.5

This is a hack but it works: before we register our classes, we call `setlocale(LC_ALL, "C");` — this will make sure that all Phalcon classes and methods will be lowercased the way we expect it. After that we restore the original locale.

The next step is to make sure that we always use lowercased names when we invoke Phalcon methods.