[libvirt] PATCH 0/0: Support setting a disk drive serial (number) v2

This is a second version of the patch posted here http://www.redhat.com/archives/libvir-list/2009-August/msg00341.html In this version, I make the QEMU driver refuse to run with any serial that doesn't contain 0-9, a-Z, -, _, since there's no way to escape special chars in QEMU command line args. Hopefully we can lift this restriction in a future version of QEMU I also add a check that serial=s is actually supported by QEMU