Change the behaviour on select date

Change the behaviour on select date - if the startDate is selected and
the user selects a valid date, the endDate is updated
Change date selection behaviur

If endData is selected, the next selection will clear the endDate and
set the startDate to the selectedDate
- prevent user to select a date earlier than today
- Show days of the week.
set header background to white color
Set to disable previous dates (earlier than today)
set calendar to disable dates earlier than today by default
Add delegate for date selection error
minir refactoring
change how TSQCalendarErrorSelectionMaxRange is fired
Disable property selection while scrolling
remove background color from NotThisMonth button - was causing weird
shadow to appear
bug fix
TSQCalendar views needs to call it’s super on layputsubviews
Merge branch 'next'