'Gets a locale item based on key.
For example, given this:
locales = {\'en\': {\'foo\': 1, \'bar\': 2},
\'it\': {\'foo\': 1, \'bar\': 2}}
You can get english foo like:
self.extract_locale(locales, \'foo\', \'en\')'

def extract_locale(self, locales, key, default=None):

    ex = {}
    for (loc, data) in locales.iteritems():
        ex[loc] = data.get(key, default)
    return ex
