New features

We have added some new features as we needed them, and I thought I'd better do a pull request if someone else needs the same things.

This is what's added:
- Possibility to set a valid date range for selection. (Based on the Eternicode datepicker startDate and endDate.)
- Possibility to set the location for the dropdown calendar. Great to have when using Bootstrap and pull-right to avoid getting the calendar outside the screen.