Softer arrival/departure time input handling

[mclaeysb]

When I need to be somewhere, say, at 11:00, I would also consider taking a train that arrives at 11:02. iRail (and nmbs/sncb) will, however, only show trains arriving at or before the time I put in. Same for departure time input.

The 'later'/'earlier' buttons are useful in this case, but since many people use these almost every time ("let me just check if there isn't a faster train that arrives just a bit later"), it could be good to either display these results by default too (and indicate the best option using color/...), or add/substract a number of minutes (say 10) from the departure/arrival time input.