[libvirt] Misc improvements to the storage driver

This patch series started out as an attempt to fix the seriously painful problem with iSCSI targets automatically logging in whenever the network came online. In the process of fixing this alot of other cruft is cleaned up docs/schemas/storagepool.rng | 5 src/conf/storage_conf.c | 21 + src/conf/storage_conf.h | 1 src/storage/storage_backend.h | 3 src/storage/storage_backend_fs.c | 29 ++ src/storage/storage_backend_iscsi.c | 427 +++++++++++++++++++++++++--------- src/storage/storage_backend_logical.c | 24 + src/storage/storage_backend_mpath.c | 20 + src/storage/storage_backend_scsi.c | 96 +++++++ src/storage/storage_driver.c | 65 +++-- tools/virsh.c | 51 ++-- 11 files changed, 573 insertions(+), 169 deletions(-) Daniel