mark Dates in the past and the future

[Schrank]

To style days in the past and the future, I needed classes for it.

Lines 362++

// Today, past and future
if (date.getFullYear() == thisYear && date.getMonth() == thisMonth && day == thisDay) {
cell.addClassName('today')
} else if (date.getFullYear() >= thisYear && date.getMonth() >= thisMonth && day >= thisDay) {
cell.addClassName('futureDay')
} else {
cell.addClassName('pastDay')
}