Add support of customization object for the method "moment.locale(...)".

[NordenF]

Moment.js allows customization of locale by dictionary-object
(docs: https://momentjs.com/docs/#/i18n/changing-locale/ )

Example:

    @bp.before_app_request
    def before_request():
        g.locale = "eo"
        g.locale_customization = {
            "longDateFormat": {
                "L": "DD.MM.YYYY",
                "LLL": "DD.MM.YYYY hh:mm",
            },
        }

    {% block scripts %}
        {{ moment.include_jquery() }}
        {{ moment.include_moment() }}
        {{ moment.locale(g.locale, customization=g.locale_customization) }}
    {% endblock %}

It should render:

	<script>
	    moment.locale('eo', {
                    'longDateFormat': {
                        'L': 'DD.MM.YYYY',
                        'LLL': 'DD.MM.YYYY hh:mm'
                    }
                }
            );
	</script>

[miguelgrinberg]

Thanks! Looks good. I'll test it out a bit before merging it.