Ed: reading time zone in GTFS

for the moment the boost tz db (why didn't they use the olson db?..) is
loaded in the repository for convenience.

real work is starting now, with the utc conversion of all the stop times
Ed: no need to init the vp to 0 it is done by default
Ed: split on dst
Ed: tz handling for GTFS

fusio still need to be done
Ed: cout cleaning before PR
Ed: conversion frequencies stop times to UTC
Ed: fusio parser to utc
Ed: default timezone in fusio
ED: add stop area's timezone to database
All: change protobuff dates from string to int

date_times are now posix time stamp (nb seconds since 1970/01/01).

when hour are given, they are express as number of seconds since
midnight)
when date are given they are express as a posix timestamp to midnight
Jormungandr: convert utc to timezone in output

All datetimes are in utc in the core, and they are converted in local
(depending on the stop area) in output
All: handle posix time from query to endpoint
Jormungandr: add a debug mode

a some misc corrections
Jormungandr: change timezone output handling

Now ALL date times are given in the dataset timezone not anymore in the
nearest stop areas time zone.
Jormungandr: add tests on journeys
Jormungandr: squeleton for split date time
Ed: corrections after review
Review: corrections after review
Jormungandr: change error code
All: merge dev