'Load additional themes placed at specified directories.'

def load_additional_themes(self, theme_paths):

    for theme_path in theme_paths:
        abs_theme_path = path.abspath(path.join(self.app.confdir, theme_path))
        themes = self.find_themes(abs_theme_path)
        for (name, theme) in iteritems(themes):
            self.themes[name] = theme
