Started work on Gettext localization

Currently everything that was previously translatable is now gettext
translatable and more using i18next javascript library. All gettext
 is automatically extracted from files with babel. PO files are then
 transformed into json with melan/i18next-gettext-converter.
Language can be set from cookie, browser or query string.
Working on opentripplanner/OpenTripPlanner#220,
opentripplanner/OpenTripPlanner#221,
opentripplanner/OpenTripPlanner#261.

TODO: Make rest of the text internationable. Find better place for
 POT and PO files.
Added some more localizations
Added all JS translations for StopFinder and Viewer widget

Other text is in HTML template. This means switching of template
language will be necessary
Added localization to Itinerary widget

TODO: print view and some other texts
BUG: In trip summary when translation is longer next label jumps to the
right and it is a little ugly
Added most translation of trip directions

Problem is with Start at, because i18next doesn't find it
Created Makefile for translations moved translations

Makefile uses pybabel to extract translations and updates them.

TODO: missing is how to actually install pybabel
Fixed makefile

Now it correctly updates POT/po and js files when files change
Added translation for Start and End
Translated transport modes. Moved i18-next to config.js

Translation language is now configured in config.js
Added translations for different modes of transport

All GTFS modes are now supported
Added all translations for TripViewer
Fixed problem with Start at translation
Added all translations for Stop finder
Added all translations for StopViewer
Translated stop layer popup
Added translations for map context menu

TODO: Start/Destination on a map Your bike/walk route on a polyline
Translated text written on routes on a map
Added translations for start and destination popups on a route
Fixed showing translated Start/Stop in Geocoder
Added translation for showing Error whn no trip is found