Convert common create/delete code to classes.

[0lvin]

Create class like:

class LibVirtObject(Object):
    def _search(object_name):
        # networkLookupByName - network
        # lookupByName - domain
        # storagePoolLookupByName - pool
        pass

   def create(properties):
        pass

   def delete(properties):
        pass

class LibVirtNetwork(LibVirtObject):
    def _search(object_name):
        # networkLookupByName - network
        pass             
    ....