[libvirt] [PATCH] storage pool discovery

Hi Folks - Here's my second pass at storage pool discovery. I've taken Daniel's suggestion and made it return a single XML doc containing <source> elements rather than an array of <pool> docs (and also incorporated suggestions from Daniel V and Jim M). Note that the storage <source> <name> patch is closely related (without it, the <source> docs returned for logical pools aren't correct). Dave