Fixes for issues #5 and #19

[saturnbee]

There is an issue with the calendars sometimes not showing the first days of the month (issue #5).

This is due to scrollcalendar relying on calendar.get(Calendar.WEEK_OF_MONTH): the first week of the month does not necessarily contains the first day of the month (see java.util.Calendar javadoc, "First Week").

The fix involves extending ScrollCalendarAdapter and MonthViewHolder to process days correctly in the latter's bind method. This has to be done in the same package as the original code because MonthViewHolder has package visibility. Not nice, but it works.

[saturnbee]

Added a fix for Issue #19.

It is now possible to select today as the first day of the last period.