New feed implementation in PageRegular

- Implemented a new Hook getPageStyleSheets and moved newsfeeds & calendarfeeds to their module configuration files and classes.

- Module News:
* Registered a new hook getPageStyleSheets
* Added a new function to \News to add the news feeds (getPageStyleSheets)

- Module Calendar:
* Registered a new hook getPageStyleSheets
* Added a new function to \Calendar to add the calendar feeds (getPageStyleSheets)