Make the kcal model deal with the no-content and invalid collection cases as well.
Make the kcal model deal with the no-content and invalid collection cases as well.

svn path=/trunk/KDE/kdepim/; revision=984081

lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi,lefou/kdepim-noakonadi