[libvirt] [docs] Couple of wiki pages with examples of live block operations

[Kashyap Chamarthy]

Heya,

Here are some examples of live block operations (to begin with, active
blockcommit) after some testing and from discussions with Eric
Blake on IRC/email:

    http://wiki.libvirt.org/page/Live-disk-backup-with-active-blockcommit
    http://wiki.libvirt.org/page/Live-merge-an-entire-disk-image-chain-including-current-active-disk

I linked the above two pages here:

    http://wiki.libvirt.org/page/Main_Page#Examples_of_live_block_opertaions

Will try to add more examples (like blockcopy, etc) and post them for
review here.

If you have comments/rewording/corrections you can provide here and I
can update the wiki or you can just edit the wiki yourself.

PS: I wondered breifly whether to post the plain text of the wiki   
content to the list but decided against it to keep the email brief :-)

-- 
/kashyap