Calendar Matrix: Create an array with the days of a month calendar

This class creates an array with the layout of the days of a given month calendar.

The class generates a calendar array given the number of the month and the year.

The generated calendar array is two dimensional. The first dimension represents the week. The second dimension represents the days of the week, so it always have 7 positions, one for each day of the week.

The array positions of days of the first or last weeks of the month that are set to 0 represent days that belong to the previous or following month respectively.