Homematic updates

Release Notes: https://github.com/openhab/openhab/wiki/Homematic-Binding

This is only a info to which server the binding is connecting. The toString method is called from the ServerId object and prints:
Homematic ServerId[name=CCU,version=2.7]
or 
Homematic ServerId[name=Homegear, version=0.5.2]

The starting messages are also written in other classes (BinRpcCallbackServer and XmlRpcCallbackServer)