KolabMailAccess: added support for list of uids for changed objects
KolabMailAccess: added support for list of uids for changed objects

* manage changed_uids per folder (using hash tables), so the query
  function (kolab_mail_access_query_changed_uids()) works on source
  names as expected
* adapted the handles update function according to InfoDb reporting
  set 'changed' flags only once, then unsetting them

GNOME/evolution-kolab,GNOME/evolution-kolab