The virConnectPtr is no longer required for error reporting since
that is recorded in a thread local. Remove use of virConnectPtr
from all APIs in node_device_conf.{h,c} and update all callers to
match

Provides the CDROM label for current media. Only implemented for the
udev backend.

* src/Makefile.am src/node_device.[ch] src/node_device_conf.[ch]
  src/node_device_hal.[ch] src/node_device_hal_linux.c
  src/qemu_driver.c src/remote_internal.c src/storage_backend.c
  src/virsh.c src/xen_unified.c tests/nodedevxml2xmltest.c
  po/POTFILES.in: implementation for node device create and destroy
  in NPIV support, patch by David Allan
Daniel