Added functions to write cpt urls in calendar

This modified version will add to the calendar url the slug of the custom post type. Example if you have a custom post type registered called 'event' with rewrite set to 'cool-events' the new functions will add 'cool-events' to all calendar links.

The only downside is that we need to flush rewrite rules manually by going to the permalink page. I tried to use a callback function when the widget is saved to run flush_rewrite_rules(); but i couldn't figure out.