Loads translation found in a directory.

        @type directory: string
        @param directory: The directory to search

        @type catalogue: MessageCatalogue
        @param catalogue: The message catalogue to dump

        @raises: ValueError

def load_messages(self, directory, catalogue):
        """
        Loads translation found in a directory.

        @type directory: string
        @param directory: The directory to search

        @type catalogue: MessageCatalogue
        @param catalogue: The message catalogue to dump

        @raises: ValueError
        """
        if not os.path.isdir(directory):
            raise ValueError("{0} is not a directory".format(directory))

        for format, loader in list(self.loaders.items()):
            extension = "{0}.{1}".format(catalogue.locale, format)
            files = find_files(directory, "*.{0}".format(extension))
            for file in files:
                domain = file.split("/")[-1][:-1 * len(extension) - 1]
                catalogue.add_catalogue(
                    loader.load(
                        file,
                        catalogue.locale,
                        domain))