Jormungandr: Lazy init of tz in utils

Conflicts:
	source/jormungandr/jormungandr/utils.py
Jormungandr: add format function in utils
Jormungandr: Cast datetime in request to integer

Conflicts:
	source/jormungandr/jormungandr/utils.py
Jormungandr: format datetimes of journeys
Jormungandr: fix scripts for v0 isochrones
Jormungandr: move find_and_transform to a mixin
Jormungandr: Fix next/prev datetimes

Conflicts:
	source/jormungandr/jormungandr/interfaces/v0/Journeys.py
jormun: small corrections to make it works
Merge pull request #498 from antoine-de/jormun_v0_datetime_pickup

Jormun v0 datetime pickup