config.py: add command line options for querying the config table.

For example:
 $ ./config has_moca -kname,ether,ip6,cpu,is_tv
 t0-2,42:42:42:42:42:12,fe80::4042:42ff:fe42:4212,BCM7425B0,1
 t0-3,42:21:06:66:aa:03,fe80::4021:6ff:fe66:aa03,BCM7425B0,1
 b2-1,00:1a:11:30:63:77,fe80::21a:11ff:fe30:6377,BCM7425B2,
 t0-4,00:03:42:21:03:69,fe80::203:42ff:fe21:369,BCM7425B0,1

Change-Id: I54679b19ea9c4ac5aee72312e539d9e441b2811f
6 files changed