Removes unnecessary qemu-img dependency on powervm driver

Fixes bug 1131033

Power VM driver is using qemu-img through the fetch_to_raw call
No need to attempt a conversion since power images can only
be represented with the raw format, removing thus the need for
any conversions by calling fetch instead of fetch_to_raw.

Change-Id: I94b46e184cb87924a4754a0a48d9c2013a3eb756
Make LibvirtDriver.uri() a staticmethod.

LibvirtDriver's uri() function seems to be the most logical place
where one can access the libvirt URL used by Nova. I would like
access to this outside the scope of the internal libvirt
driver (for libguestfs) so exposing it as a static
resource seems to make sense.

Partial fix for LP Bug #1131768.

Change-Id: I653296414716b4e799d68f6bfc868e6039d6ea4a
Make guestfs use same libvirt URI as Nova.

Updates our libguestfs vfs implementation so that it makes use of
the same libvirt connection URI as Nova does when using
attach mode 'libvirt'. Previously when libguestfs used attach
mode 'libvirt' (the default on some newer distros like Fedora 18)
you could get permissions issues and ultimately get a libvirt
connection error from libguestfs:

  could not connect to libvirt (URI = NULL)

Docs on guestfs attach method can be found here:

  http://libguestfs.org/guestfs.3.html#attach-method

Having libguestfs use the same connection URL as Nova makes sense
and gets past these permission issues. (avoiding things like forcing
you to create a $HOME dir for the nova user among other things)

Full thread on this is here:

  https://bugzilla.redhat.com/show_bug.cgi?id=913345

Note that on most distros the default libguestfs attach method
is still 'appliance' so this would have no affect unless explicitly
enabled via LIBGUESTFS_ATTACH_METHOD.

Fixes LP Bug #1131768.

Change-Id: I7e9f010022731a43e8d793cf8415ec12b346fdb4
Add missing import_opt for flat_injected

Fixes bug 1131891

Change-Id: I993798abea27b8d37efe5d3c122a490d85e192a8
Merge "Add missing import_opt for flat_injected"
Merge "Make LibvirtDriver.uri() a staticmethod."
Merge "Make guestfs use same libvirt URI as Nova."
Merge "Removes unnecessary qemu-img dependency on powervm driver"
Merge remote-tracking branch 'm_src_repo/master' into build-temp