[Libvirt-cim] Remove enumerate() function in device.py and update tc to call new function in enumclass.py

Hi, Do you think it's better to remove enumerate() function in device.py? Then we have to update tc to call new EnumInstances() function in enumclass.py. Who would like to take up this work? If not, I will cook up these patches. Thanks! Best, Regards Daisy (运国莲) VSM Team, China Systems & Technology Labs (CSTL) E-mail: yunguol(a)cn.ibm.com TEL: (86)-21-60922403 Building 10, 399 Ke Yuan Rd, Pudong Shanghai, 201203