Fix for -1 row in calculateDayCellFrame
Fix for -1 row in calculateDayCellFrame

NSWeekOfMonthCalendarUnit returns zero for week number sometimes,
better solution is to use the week of year, subtracting the week of
year value for the first day of the month (which we have in
_monthShowing)

reifrontier/RFLCalendar,mofojed/CKCalendar