Simple Date Handler

Small and simple Java Date handler library, based on public static methods for basic java.util.Date manipulation.

The main features:
- add minutes, hours, seconds to a given date;
- get the hour 00:00:00 and 23:59:59 from a given date;
- get the diference in hours, minutes, seconds between 2 given dates;
- check if 2 or more dates are in the same week, month;
- check if 2 or more dates are the same day;
- get the start and end of the month;