Changes to DataEngine:
* Change request API to take a list of Holiday Regions to return Holidays for
* Add new "holidaysRegion" request to return details about a Holiday Region
* Use new KHolidays API for Holiday Duration to return a single Holiday Event
  for multiday holidays, rather than multiple events.
* Change return API data keys to make changed behaviour obvious

Changes to CalendarTable:
* Enable displaying multiple Holiday Regions at once
* Enable using holiday duration

Note that multiple holiday regions cannot be manually configured as yet as
this will use a new common widget from KHolidays that I am still writing, I
just need a working client to test it on :-)


svn path=/trunk/KDE/kdebase/workspace/; revision=1178605