update ChangeLog to 2.7.0
update ChangeLog to 2.7.0

kkaempf/openwsman,Openwsman/openwsman,Openwsman/openwsman,Openwsman/openwsman,kkaempf/openwsman,Openwsman/openwsman,Openwsman/openwsman,vcrhonek/openwsman,vcrhonek/openwsman,vcrhonek/openwsman,Openwsman/openwsman,kkaempf/openwsman,vcrhonek/openwsman,Openwsman/openwsman,kkaempf/openwsman,kkaempf/openwsman,vcrhonek/openwsman,kkaempf/openwsman,kkaempf/openwsman,vcrhonek/openwsman,vcrhonek/openwsman