[libvirt] [PATCH 0/3 v3] New command for changing media

[Osier Yang]

[PATCH 0/3] introduces two new helper functions: vshFindDisk is to find
the disk XML node in xml doc with the type (indicates it's normal disk
or changeable disk). VshPrepareDiskXML is to prepare the disk XML for
disk changing commands' use, such as detach-disk. The purpose of this
patch is to prepare for upcoming new command "change-disk", which will
use the two helper functions too.

Please see [PATCH 3/3] for a overall description of the new command.

v2 - v3
  * Update vshFindDisk to support search the disk node with both
    the source path and target name.
  * Change names of the two new enums ([PATCH 1/3]).
  * Use virXMLParseStringCtxt instead of xmlReadDoc
  * Use VIR_ALLOC_N instead of vshCalloc.
  * [PATCH 3/4] and [PATCH 4/4] are merged into [PATCH 3/3]
  * Change option "--target" into "--path".
  * Defaults to use "--update" if none of "--eject", "--insert",
    and "--update" is specified.
  * Update docs to be consistent with the changes on codes.
  * Other nits.

[PATCH 1/3] virsh: Two new helper functions for disk device changes
[PATCH 2/3] virsh: Use vshFindDisk and vshPrepareDiskXML in cmdDetachDisk
[PATCH 3/3] virsh: New command cmdChangeMedia

Regards,
Osier