- add support for plural forms in context texts

- port all ActionManagers to make use of plural form context texts
- add support for mass deletion/synchronization of collections
- made action texts for collection deletion/synchronization plural form aware
- renamed DeleteResource/SynchronizeResource to DeleteResources/SynchronizeResources
  to be consistent with DeleteCollections/SynchronizeCollections

svn path=/trunk/KDE/kdepimlibs/; revision=1171229