device_info.py: implement some of the counters as trivial properties.
device_info.py: implement some of the counters as trivial properties.

Instead of just hardcoding them to zero regardless of the length of their
lists.  Doesn't really make much difference for now since the lists are
still always zero.

pombredanne/catawampus,ankurjimmy/catawampus,pombredanne/catawampus,ankurjimmy/catawampus,shineyear/catawampus,shineyear/catawampus,ultilix/catawampus,ultilix/catawampus