Globals fix

Store response and application (default) locale in the "locale" property of the respective locals objects.
Attach gettext instance on application's settings to avoid some unnecessary closures
Switch methods from request object to response object and make method names uniform
Store locale in normalized form and always lookup translation using uniform locale key transformation
Improved checks for null

Bump version to 0.2 because of API changes (old methods kept around for backward compatibility)
I actually made the same mistake when I first wrote this and it failed very quickly ;)