Expose the disk-only flag through virsh. Additionally, make
virsh snapshot-create-as take an arbitrary number of diskspecs,
which can be used to build up the xml for <domainsnapshot>.
* tools/virsh.c (cmdSnapshotCreate): Add --disk-only.
(cmdSnapshotCreateAs): Likewise, and add argv diskspec.
(vshParseSnapshotDiskspec): New helper function.
(vshCmddefGetOption): Allow naming of argv field.
* tools/virsh.pod (snapshot-create, snapshot-create-as): Document
them.
* tests/virsh-optparse: Test snapshot-create-as parsing.
The last patch breaks make check for two reasons. First, it reverses the
condition but leaves default level unchanged, so instead of not printing
anything but errors before the patch it now prints all debug messages by
default. Second, you forgot to change -d5 option passed to virsh in
tests/virsh-optparse to -d0; the script wants to see all debug messages.
