- teeny fix to ll_revalidate2; this will be trumped by my fix for 626244

- teeny fix to ll_revalidate2; this will be trumped by my fix for 626244
  in ways that can scarcely be described by mere words
- multiple CONNECTs to the LOV would do more CONNECTs to the OSCs, each
  clobbering the last connection and preventing cleanup; fixed.
- LOV targets now have an 'active' bit; inactive targets will be skipped at
  CREATE and DISCONNECT time
- added locking for the above, along with a function to toggle the bit given an
  LOV and a UUID
- added a LOV_SET_OSC_ACTIVE ioctl to the lov driver and lctl