Add a whole bunch of resource-specific sanity checking for change

notifications to ResourceBase. Some resources (mainly noticed and tested
with maildir) don't handle eg. change notifications without RIDs very
well. These should not happen of course, but sometimes do, if the
initial add to the resource failed for whatever reason.

Now we at least prevent random misbehavior or asserts there, but it would
also be possible to add recovery code for those cases and retry adding
the RID-less objects for example.

svn path=/trunk/KDE/kdepimlibs/; revision=1208589