Fix #375 - Modified key to disable updates in order to avoid conflict with refresh servers.
Fix #373 - Corrected minor defects displaying realtime info: negative early arrivals and added support for minutes in singular.
Fix #356 - Added mapbox tiles and set as default.
Fix #356 - Improved mapbox tiles, adding a 256x256 server that would be default for lower than hdpi and the 512x512 for the other devices. New options are "mapbox" and "mapbox retina".
I have tested 256x256 tiles on a hdpi to see if would be good to include this res in the low group but there is a very important difference, specially when zooming.
Merge pull request #377 from vreixo/issue375

Fix #375 - Modified key to disable updates in order to avoid conflict wi...
Merge pull request #379 from vreixo/issue373

Fix #373 - Corrected minor defects displaying realtime info: negative ea...
Merge pull request #380 from vreixo/issue356

Fix #356 - Added mapbox faster servers with 256x256 and 512x512 tiles.
Fix #382 - Updated Galician and Spanish translations.
Fix #385 - Corrected duration function to don't return null on more than a day long.
Fix #387 - Redesigned step-by-step instructions.
Merge pull request #383 from vreixo/issue382

Fix #382 - Updated Galician and Spanish translations.
Merge pull request #386 from vreixo/issue385

Fix #385 - Corrected duration function to don't return null on more than...
Merge pull request #388 from vreixo/issue387

Fix #387 - Redesigned step-by-step instructions.