Config interface now uses the new struct lustre_cfg for all config

Config interface now uses the new struct lustre_cfg for all config
commands.  Config commands are sent by lctl using the
OBD_IOC_PROCESS_CFG ioctl, and they can be recorded with
OBD_IOC_RECORD (untested). The configuration process is now stateless,
and each command refers to the device it operates on by name, if
needed.  The lctl interface has changed slightly:

* newdev is not needed. (It continues to exist for compatibility, but
  is a NOOP.)  The attach command now selects the new device.

* cfg_device <name> is used to select the device that is being
  configured. This takes the place of the "device; probe" for config
  commands only.

The current config ops are:
        LCFG_ATTACH
        LCFG_DETACH
        LCFG_SETUP
        LCFG_CLEANUP
        LCFG_LOV_SET_CONFIG
        LCFG_ADD_UUID
        LCFG_DEL_UUID

The other ioctls are unchanged. The portals config commands have not
been incorporated yet.