KolabMailObject: bugfixes, added debug output
KolabMailObject: bugfixes, added debug output

* added missing NULL return in kolab_mail_handle_new_from_ecalcomponent
  (if timezone param is set but of wrong ECalComponent type)
* corrected timezone vs. priv->timezone NULL check (fixes a GObject
  type warning)
* added lots of g_debug() and g_warning() output

GNOME/evolution-kolab,GNOME/evolution-kolab